spack.util package


spack.util.compression module

spack.util.compression.decompressor_for(path, extension=None)

Get the appropriate decompressor for a path.


Get the archive extension for a path.


Get the part of a path that does not include its compressed type extension.

spack.util.crypto module

class spack.util.crypto.Checker(hexdigest, **kwargs)

Bases: object

A checker checks files against one particular hex digest. It will automatically determine what hashing algorithm to used based on the length of the digest it’s initialized with. e.g., if the digest is 32 hex characters long this will use md5.

Example: know your tarball should hash to ‘abc123’. You want to check files against this. You would use this class like so:

hexdigest = 'abc123'
checker = Checker(hexdigest)
success = checker.check('downloaded.tar.gz')

After the call to check, the actual checksum is available in checker.sum, in case it’s needed for error output.

You can trade read performance and memory usage by adjusting the block_size optional arg. By default it’s a 1MB (2**20 bytes) buffer.


Read the file with the specified name and check its checksum against self.hexdigest. Return True if they match, False otherwise. Actual checksum is stored in self.sum.


Get the name of the hash function this Checker is using.

class spack.util.crypto.DeprecatedHash(hash_alg, alert_fn, disable_security_check)

Bases: object


Number of bits required to represent an integer in binary.

spack.util.crypto.checksum(hashlib_algo, filename, **kwargs)

Returns a hex digest of the filename generated using an algorithm from hashlib.


Gets name of the hash algorithm for a hex digest.


Get a function that can perform the specified hash algorithm.


Gets a hash function corresponding to a hex digest.

spack.util.crypto.hashes = {'md5': 16, 'sha1': 20, 'sha224': 28, 'sha256': 32, 'sha384': 48, 'sha512': 64}

Set of hash algorithms that Spack can use, mapped to digest size in bytes

spack.util.crypto.prefix_bits(byte_array, bits)

Return the first <bits> bits of a byte array as an integer.

spack.util.debug module

Debug signal handler: prints a stack trace and enters interpreter.

register_interrupt_handler() enables a ctrl-C handler that prints a stack trace and drops the user into an interpreter.

spack.util.debug.debug_handler(sig, frame)

Interrupt running process, and provide a python prompt for interactive debugging.


Print traceback and enter an interpreter on Ctrl-C

spack.util.editor module

Module for finding the user’s preferred text editor.

Defines one function, editor(), which invokes the editor defined by the user’s VISUAL environment variable if set. We fall back to the editor defined by the EDITOR environment variable if VISUAL is not set or the specified editor fails (e.g. no DISPLAY for a graphical editor). If neither variable is set, we fall back to one of several common editors, raising an EnvironmentError if we are unable to find one.

spack.util.editor.editor(*args, **kwargs)

Invoke the user’s editor.

This will try to execute the following, in order:

  1. $VISUAL <args> # the “visual” editor (per POSIX)

  2. $EDITOR <args> # the regular editor (per POSIX)

  3. some default editor (see _default_editors) with <args>

If an environment variable isn’t defined, it is skipped. If it points to something that can’t be executed, we’ll print a warning. And if we can’t find anything that can be executed after searching the full list above, we’ll raise an error.


args (list of str) – args to pass to editor

Optional Arguments:

_exec_func (function): invoke this function instead of os.execv()

spack.util.environment module

Utilities for setting and modifying environment variables.

class spack.util.environment.AppendFlagsEnv(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.AppendPath(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.DeprioritizeSystemPaths(name, **kwargs)

Bases: spack.util.environment.NameModifier

class spack.util.environment.EnvironmentModifications(other=None)

Bases: object

Keeps track of requests to modify the current environment.

Each call to a method to modify the environment stores the extra information on the caller in the request:

  • ‘filename’ : filename of the module where the caller is defined

  • ‘lineno’: line number where the request occurred

  • ‘context’ : line of code that issued the request that failed

append_flags(name, value, sep=' ', **kwargs)

Stores in the current object a request to append to an env variable

  • name – name of the environment variable to be appended to

  • value – value to append to the environment variable

Appends with spaces separating different additions to the variable

append_path(name, path, **kwargs)

Stores a request to append a path to a path list.

  • name – name of the path list in the environment

  • path – path to be appended


Applies the modifications and clears the list.


Clears the current list of modifications

deprioritize_system_paths(name, **kwargs)

Stores a request to deprioritize system paths in a path list, otherwise preserving the order.


name – name of the path list in the environment.

static from_environment_diff(before, after, clean=False)

Constructs an instance of a spack.util.environment.EnvironmentModifications object from the diff of two dictionaries.

  • before (dict) – environment before the modifications are applied

  • after (dict) – environment after the modifications are applied

  • clean (bool) – in addition to removing empty entries, also remove duplicate entries

static from_sourcing_file(filename, *arguments, **kwargs)

Constructs an instance of a spack.util.environment.EnvironmentModifications object that has the same effect as sourcing a file.

  • filename (str) – the file to be sourced

  • *arguments (list of str) – arguments to pass on the command line

Keyword Arguments
  • shell (str) – the shell to use (default: bash)

  • shell_options (str) – options passed to the shell (default: -c)

  • source_command (str) – the command to run (default: source)

  • suppress_output (str) – redirect used to suppress output of command (default: &> /dev/null)

  • concatenate_on_success (str) – operator used to execute a command only when the previous command succeeds (default: &&)

  • blacklist ([str or re]) – ignore any modifications of these variables (default: [])

  • whitelist ([str or re]) – always respect modifications of these variables (default: []). has precedence over blacklist.

  • clean (bool) – in addition to removing empty entries, also remove duplicate entries (default: False).


Returns a dict of the modifications grouped by variable name.


dict mapping the environment variable name to the modifications to be done on it

prepend_path(name, path, **kwargs)

Same as append_path, but the path is pre-pended.

  • name – name of the path list in the environment

  • path – path to be pre-pended

prune_duplicate_paths(name, **kwargs)

Stores a request to remove duplicates from a path list, otherwise preserving the order.


name – name of the path list in the environment.

remove_flags(name, value, sep=' ', **kwargs)

Stores in the current object a request to remove flags from an env variable

  • name – name of the environment variable to be removed from

  • value – value to remove to the environment variable

  • sep – separator to assume for environment variable

remove_path(name, path, **kwargs)

Stores a request to remove a path from a path list.

  • name – name of the path list in the environment

  • path – path to be removed


Returns the EnvironmentModifications object that will reverse self

Only creates reversals for additions to the environment, as reversing unset and remove_path modifications is impossible.

Reversable operations are set(), prepend_path(), append_path(), set_path(), and append_flags().

set(name, value, **kwargs)

Stores a request to set an environment variable.

  • name – name of the environment variable to be set

  • value – value of the environment variable

set_path(name, elements, **kwargs)

Stores a request to set a path generated from a list.

  • name – name o the environment variable to be set.

  • elements – elements of the path to set.


Return shell code to apply the modifications and clears the list.

unset(name, **kwargs)

Stores a request to unset an environment variable.


name – name of the environment variable to be set

class spack.util.environment.NameModifier(name, **kwargs)

Bases: object

class spack.util.environment.NameValueModifier(name, value, **kwargs)

Bases: object

class spack.util.environment.PrependPath(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.PruneDuplicatePaths(name, **kwargs)

Bases: spack.util.environment.NameModifier

class spack.util.environment.RemoveFlagsEnv(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.RemovePath(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.SetEnv(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.SetPath(name, value, **kwargs)

Bases: spack.util.environment.NameValueModifier

class spack.util.environment.UnsetEnv(name, **kwargs)

Bases: spack.util.environment.NameModifier

spack.util.environment.concatenate_paths(paths, separator=':')

Concatenates an iterable of paths into a string of paths separated by separator, defaulting to colon.

  • paths – iterable of paths

  • separator – the separator to use, default ‘:’




Put system paths at the end of paths, otherwise preserving order.

spack.util.environment.dump_environment(path, environment=None)

Dump an environment dictionary to a source-able file.

spack.util.environment.env_var_to_source_line(var, val)
spack.util.environment.environment_after_sourcing_files(*files, **kwargs)

Returns a dictionary with the environment that one would have after sourcing the files passed as argument.


*files – each item can either be a string containing the path of the file to be sourced or a sequence, where the first element is the file to be sourced and the remaining are arguments to be passed to the command line

Keyword Arguments
  • env (dict) – the initial environment (default: current environment)

  • shell (str) – the shell to use (default: /bin/bash)

  • shell_options (str) – options passed to the shell (default: -c)

  • source_command (str) – the command to run (default: source)

  • suppress_output (str) – redirect used to suppress output of command (default: &> /dev/null)

  • concatenate_on_success (str) – operator used to execute a command only when the previous command succeeds (default: &&)

spack.util.environment.filter_environment_blacklist(env, variables)

Generator that filters out any change to environment variables present in the input list.

  • env – list of environment modifications

  • variables – list of variable names to be filtered


items in env if they are not in variables


Return only paths that are not system paths.

spack.util.environment.inspect_path(root, inspections, exclude=None)

Inspects root to search for the subdirectories in inspections. Adds every path found to a list of prepend-path commands and returns it.

  • root (str) – absolute path where to search for subdirectories

  • inspections (dict) – maps relative paths to a list of environment variables that will be modified if the path exists. The modifications are not performed immediately, but stored in a command object that is returned to client

  • exclude (callable) – optional callable. If present it must accept an absolute path and return True if it should be excluded from the inspection


The following lines execute an inspection in /usr to search for /usr/include and /usr/lib64. If found we want to prepend /usr/include to CPATH and /usr/lib64 to MY_LIB64_PATH.

# Set up the dictionary containing the inspection
inspections = {
    'include': ['CPATH'],
    'lib64': ['MY_LIB64_PATH']

# Get back the list of command needed to modify the environment
env = inspect_path('/usr', inspections)

# Eventually execute the commands

instance of EnvironmentModifications containing the requested modifications


Predicate that given a path returns True if it is a system path, False otherwise.


path (str) – path to a directory


True or False

spack.util.environment.path_put_first(var_name, directories)

Puts the provided directories first in the path, adding them if they’re not already there.

spack.util.environment.path_set(var_name, directories)
spack.util.environment.pickle_environment(path, environment=None)

Pickle an environment dictionary to a file.


Ensures that the value of the environment variables passed as arguments is the same before entering to the context manager and after exiting it.

Variables that are unset before entering the context manager will be explicitly unset on exit.


variables (list of str) – list of environment variables to be preserved


Returns the paths with duplicates removed, order preserved.

spack.util.environment.sanitize(environment, blacklist, whitelist)

Returns a copy of the input dictionary where all the keys that match a blacklist pattern and don’t match a whitelist pattern are removed.

  • environment (dict) – input dictionary

  • blacklist (list of str) – literals or regex patterns to be blacklisted

  • whitelist (list of str) – literals or regex patterns to be whitelisted


Temporarily sets and restores environment variables.

Variables can be set as keyword arguments to this function.

spack.util.environment.set_or_unset_not_first(variable, changes, errstream)

Check if we are going to set or unset something after other modifications have already been requested.

spack.util.environment.validate(env, errstream)

Validates the environment modifications to check for the presence of suspicious patterns. Prompts a warning for everything that was found.

Current checks: - set or unset variables after other changes on the same variable


env – list of environment modifications

spack.util.executable module

class spack.util.executable.Executable(name)

Bases: object

Class representing a program that can be run on the command line.


Add a default argument to the command.

add_default_env(key, value)

Set an environment variable when the command is run.

  • key – The environment variable to set

  • value – The value to set it to


The command-line string.


The executable and default arguments

Return type



The executable name.


The basename of the executable

Return type



The path to the executable.


The path to the executable

Return type


spack.util.executable.which(*args, **kwargs)

Finds an executable in the path like command-line which.

If given multiple executables, returns the first one that is found. If no executables are found, returns None.


*args (str) – One or more executables to search for

Keyword Arguments
  • path (list() or str) – The path to search. Defaults to PATH

  • required (bool) – If set to True, raise an error if executable not found


The first executable that is found in the path

Return type


exception spack.util.executable.ProcessError(message, long_message=None)

Bases: spack.error.SpackError

ProcessErrors are raised when Executables exit with an error code.

spack.util.file_cache module

exception spack.util.file_cache.CacheError(message, long_message=None)

Bases: spack.error.SpackError

class spack.util.file_cache.FileCache(root, timeout=120)

Bases: object

This class manages cached data in the filesystem.

  • Cache files are fetched and stored by unique keys. Keys can be relative paths, so that there can be some hierarchy in the cache.

  • The FileCache handles locking cache files for reading and writing, so client code need not manage locks for cache entries.


Path to the file in the cache for a particular key.


Remove all files under the cache root.


Ensure we can access a cache file. Create a lock for it if needed.

Return whether the cache file exists yet or not.


Return modification time of cache file, or 0 if it does not exist.

Time is in units returned by os.stat in the mtime field, which is platform-dependent.


Get a read transaction on a file cache item.

Returns a ReadTransaction context manager and opens the cache file for reading. You can use it like this:

with file_cache_object.read_transaction(key) as cache_file:


Get a write transaction on a file cache item.

Returns a WriteTransaction context manager that opens a temporary file for writing. Once the context manager finishes, if nothing went wrong, moves the file into place on top of the old file atomically.

spack.util.file_permissions module

exception spack.util.file_permissions.InvalidPermissionsError(message, long_message=None)

Bases: spack.error.SpackError

Error class for invalid permission setters

spack.util.file_permissions.set_permissions(path, perms, group=None)
spack.util.file_permissions.set_permissions_by_spec(path, spec)

spack.util.gpg module

class spack.util.gpg.Gpg

Bases: object

classmethod create(**kwargs)
classmethod export_keys(location, *keys)
static gpg()
classmethod list(trusted, signing)
classmethod sign(key, file, output, clearsign=False)
classmethod signing_keys()
classmethod trust(keyfile)
classmethod untrust(signing, *keys)
classmethod verify(signature, file, suppress_warnings=False)

spack.util.lock module

Wrapper for llnl.util.lock allows locking to be enabled/disabled.

class spack.util.lock.Lock(*args, **kwargs)

Bases: llnl.util.lock.Lock

Lock that can be disabled.

This overrides the _lock() and _unlock() methods from llnl.util.lock so that all the lock API calls will succeed, but the actual locking mechanism can be disabled via _enable_locks.


Do some extra checks to ensure disabling locks is safe.

This will raise an error if path can is group- or world-writable AND the current user can write to the directory (i.e., if this user AND others could write to the path).

This is intended to run on the Spack prefix, but can be run on any path for testing.

spack.util.log_parse module

spack.util.log_parse.parse_log_events(stream, context=6, jobs=None, profile=False)

Extract interesting events from a log file as a list of LogEvent.

  • stream (str or fileobject) – build log name or file object

  • context (int) – lines of context to extract around each log event

  • jobs (int) – number of jobs to parse with; default ncpus

  • profile (bool) – print out profile information for parsing


two lists containig BuildError and

BuildWarning objects.

Return type


This is a wrapper around ctest_log_parser.CTestLogParser that lazily constructs a single CTestLogParser object. This ensures that all the regex compilation is only done once.

spack.util.log_parse.make_log_context(log_events, width=None)

Get error context from a log file.

  • log_events (list of LogEvent) – list of events created by ctest_log_parser.parse()

  • width (int or None) – wrap width; 0 for no limit; None to auto-size for terminal


context from the build log with errors highlighted

Return type


Parses the log file for lines containing errors, and prints them out with line numbers and context. Errors are highlighted with ‘>>’ and with red highlighting (if color is enabled).

Events are sorted by line number before they are displayed.

spack.util.module_cmd module

This module contains routines related to the module command for accessing and parsing environment modules.


Inspects a TCL module for entries that indicate the absolute path at which the library supported by said module can be found.

spack.util.module_cmd.get_path_from_module_contents(text, module_name)

Takes a module name and removes modules until it is possible to load that module. It then loads the provided module. Depends on the modulecmd implementation of modules used in cray and lmod.


spack.util.naming module


Convert a name from module style to class name style. Spack mostly follows PEP-8:

  • Module and package names use lowercase_with_underscores.

  • Class names use the CapWords convention.

Regular source code follows these convetions. Spack is a bit more liberal with its Package names and Compiler names:

  • They can contain ‘-‘ as well as ‘_’, but cannot start with ‘-‘.

  • They can start with numbers, e.g. “3proxy”.

This function converts from the module convention to the class convention by removing _ and - and converting surrounding lowercase text to CapWords. If mod_name starts with a number, the class name returned will be prepended with ‘_’ to make a valid Python identifier.


Given a Spack module name, returns the name by which it can be imported in Python.


Return whether mod_name is valid for use in Spack.


Return whether mod_name is a valid namespaced module name.


Raise an exception if mod_name is not a valid namespaced module name.


Raise an exception if mod_name is not valid.


Given a Python module name, return a list of all possible spack module names that could correspond to it.


Simplify package name to only lowercase, digits, and dashes.

Simplifies a name which may include uppercase letters, periods, underscores, and pluses. In general, we want our package names to only contain lowercase letters, digits, and dashes.


name (str) – The original name of the package


The new name of the package

Return type


class spack.util.naming.NamespaceTrie(separator='.')

Bases: object

class Element(value)

Bases: object


True if there is a value set for the given namespace.


True if this namespace has no children in the trie.


True if the namespace has a value, or if it’s the prefix of one that does.

spack.util.package_hash module

exception spack.util.package_hash.PackageHashError(message, long_message=None)

Bases: spack.error.SpackError

Raised for all errors encountered during package hashing.

class spack.util.package_hash.RemoveDirectives(spec)

Bases: ast.NodeTransformer

Remove Spack directives from a package AST.

class spack.util.package_hash.RemoveDocstrings

Bases: ast.NodeTransformer

Transformer that removes docstrings from a Python AST.

class spack.util.package_hash.ResolveMultiMethods(methods)

Bases: ast.NodeTransformer

Remove methods which do not exist if their @when is not satisfied.

class spack.util.package_hash.TagMultiMethods(spec)

Bases: ast.NodeVisitor

Tag @when-decorated methods in a spec.

spack.util.package_hash.package_hash(spec, content=None)

spack.util.path module

Utilities for managing paths in Spack.

TODO: this is really part of spack.config. Consolidate it.


Substitute placeholders into paths.

Spack allows paths in configs to have some placeholders, as follows:

  • $spack The Spack instance’s prefix

  • $user The current user’s username

  • $tempdir Default temporary directory returned by tempfile.gettempdir()

These are substituted case-insensitively into the path, and users can use either $var or ${var} syntax for the variables.


Substitute config vars, expand environment vars, expand user home.


Same as substitute_path_variables, but also take absolute path.

spack.util.pattern module

class spack.util.pattern.Args(*flags, **kwargs)

Bases: spack.util.pattern.Bunch

Subclass of Bunch to write argparse args more naturally.

class spack.util.pattern.Bunch(**kwargs)

Bases: object

Carries a bunch of named attributes (from Alex Martelli bunch)

spack.util.pattern.composite(interface=None, method_list=None, container=<class 'list'>)

Decorator implementing the GoF composite pattern.

  • interface (type) – class exposing the interface to which the composite object must conform. Only non-private and non-special methods will be taken into account

  • method_list (list of str) – names of methods that should be part of the composite

  • container (MutableSequence) – container for the composite object (default = list). Must fulfill the MutableSequence contract. The composite class will expose the container API to manage object composition


a class decorator that patches a class adding all the methods it needs to be a composite for a given interface.

spack.util.prefix module

This file contains utilities for managing the installation prefix of a package.

class spack.util.prefix.Prefix

Bases: str

This class represents an installation prefix, but provides useful attributes for referring to directories inside the prefix.

Attributes of this object are created on the fly when you request them, so any of the following is valid:

>>> prefix = Prefix('/usr')
>>> prefix.bin
>>> prefix.lib64
>>> prefix.join('dashed-directory').bin64

Prefix objects behave identically to strings. In fact, they subclass str. So operators like + are legal:

print('foobar ' + prefix)

This prints foobar /usr. All of this is meant to make custom installs easy.


Concatenates a string to a prefix.


string (str) – the string to append to the prefix


the newly created installation prefix

Return type


spack.util.s3 module


spack.util.spack_json module

Simple wrapper around JSON to guarantee consistent use of load/dump.


Spack JSON needs to be ordered to support specs.

spack.util.spack_json.dump(data, stream=None)

Dump JSON with a reasonable amount of indentation and separation.

exception spack.util.spack_json.SpackJSONError(msg, json_error)

Bases: spack.error.SpackError

Raised when there are issues with JSON parsing.

spack.util.spack_yaml module

Enhanced YAML parsing for Spack.

  • load() preserves YAML Marks on returned objects – this allows us to access file and line information later.

  • Our load methods use ``OrderedDict class instead of YAML’s default unorderd dict.

spack.util.spack_yaml.load(*args, **kwargs)
spack.util.spack_yaml.dump(obj, default_flow_style=False, stream=None)
exception spack.util.spack_yaml.SpackYAMLError(msg, yaml_error)

Bases: spack.error.SpackError

Raised when there are issues with YAML parsing.

spack.util.string module

spack.util.string.comma_list(sequence, article='')
spack.util.string.plural(n, singular, plural=None, show_n=True)

Pluralize <singular> word by adding an s if n != 1.

  • n (int) – number of things there are

  • singular (str) – singular form of word

  • plural (str, optional) – optional plural form, for when it’s not just singular + ‘s’

  • show_n (bool) – whether to include n in the result string (default True)


“1 thing” if n == 1 or “n things” if n != 1

Return type


spack.util.string.quote(sequence, q="'")

spack.util.url module

Utility functions for parsing, formatting, and manipulating URLs.


Format a URL string

Returns a canonicalized format of the given URL as a string.

spack.util.url.join(base_url, path, *extra, **kwargs)

Joins a base URL with one or more local URL path components

If resolve_href is True, treat the base URL as though it where the locator of a web page, and the remaining URL path components as though they formed a relative URL to be resolved against it (i.e.: as in os.path.join(…)). The result is an absolute URL to the resource to which a user’s browser would navigate if they clicked on a link with an “href” attribute equal to the relative URL.

If resolve_href is False (default), then the URL path components are joined as in os.path.join().

Note: file:// URL path components are not canonicalized as part of this operation. To canonicalize, pass the joined url to format().


base_url = ‘s3://bucket/index.html’ body = fetch_body(prefix) link = get_href(body) # link == ‘../other-bucket/document.txt’

# wrong - link is a local URL that needs to be resolved against base_url spack.util.url.join(base_url, link) ‘s3://bucket/other_bucket/document.txt’

# correct - resolve local URL against base_url spack.util.url.join(base_url, link, resolve_href=True) ‘s3://other_bucket/document.txt’

prefix = ‘

# wrong - prefix is just a URL prefix spack.util.url.join(prefix, ‘my-package’, resolve_href=True) ‘

# correct - simply append additional URL path components spack.util.url.join(prefix, ‘my-package’, resolve_href=False) # default ‘

# For canonicalizing file:// URLs, take care to explicitly differentiate # between absolute and relative join components.

# ‘$spack’ is not an absolute path component join_result = spack.util.url.join(‘/a/b/c’, ‘$spack’) ; join_result ‘file:///a/b/c/$spack’ spack.util.url.format(join_result) ‘file:///a/b/c/opt/spack

# ‘/$spack’ is an absolute path component join_result = spack.util.url.join(‘/a/b/c’, ‘/$spack’) ; join_result ‘file:///$spack’ spack.util.url.format(join_result) ‘file:///opt/spack


Get a local file path from a url.

If url is a file:// URL, return the absolute path to the local file or directory referenced by it. Otherwise, return None.

spack.util.url.parse(url, scheme='file')

Parse a url.

For file:// URLs, the netloc and path components are concatenated and passed through spack.util.path.canoncalize_path().

Otherwise, the returned value is the same as urllib’s urlparse() with allow_fragments=False.

spack.util.web module

exception spack.util.web.HTMLParseError

Bases: Exception

class spack.util.web.LinkParser

Bases: html.parser.HTMLParser

This parser just takes an HTML page and strips out the hrefs on the links. Good enough for a really simple spider.

handle_starttag(tag, attrs)
exception spack.util.web.NoNetworkConnectionError(message, url)

Bases: spack.util.web.SpackWebError

Raised when an operation can’t get an internet connection.

class spack.util.web.NonDaemonContext

Bases: multiprocessing.context.ForkContext


alias of NonDaemonProcess

class spack.util.web.NonDaemonPool(*args, **kwargs)

Bases: multiprocessing.pool.Pool

Pool that uses non-daemon processes

class spack.util.web.NonDaemonProcess(group=None, target=None, name=None, args=(), kwargs={}, *, daemon=None)

Bases: multiprocessing.context.Process

Process that allows sub-processes, so pools can have sub-pools.


Return whether process is a daemon

exception spack.util.web.SpackWebError(message, long_message=None)

Bases: spack.error.SpackError

Superclass for Spack web spidering errors.

spack.util.web.find_versions_of_archive(archive_urls, list_url=None, list_depth=0)

Scrape web pages for new versions of a tarball.


archive_urls (str or list or tuple) – URL or sequence of URLs for different versions of a package. Typically these are just the tarballs from the package file itself. By default, this searches the parent directories of archives.

Keyword Arguments
  • list_url (str or None) – URL for a listing of archives. Spack will scrape these pages for download links that look like the archive URL.

  • list_depth (int) – Max depth to follow links on list_url pages. Defaults to 0.

spack.util.web.push_to_url(local_file_path, remote_path, **kwargs)
spack.util.web.read_from_url(url, accept_content_type=None)
spack.util.web.spider(root, depth=0)

Gets web pages from a root URL.

If depth is specified (e.g., depth=2), then this will also follow up to <depth> levels of links from the root.

This will spawn processes to fetch the children, for much improved performance over a sequential fetch.


Replace certain header names with standardized spellings.

Standardizes the spellings of the following header names: - Accept-ranges - Content-length - Content-type - Date - Last-modified - Server

Every name considered is translated to one of the above names if the only difference between the two is how the first letters of each word are capitalized; whether words are separated; or, if separated, whether they are so by a dash (-), underscore (_), or space ( ). Header names that cannot be mapped as described above are returned unaltered.

For example: The standard spelling of “Content-length” would be substituted for any of the following names: - Content-length - content_length - contentlength - content_Length - contentLength - content Length

… and any other header name, such as “Content-encoding”, would not be altered, regardless of spelling.

If headers is a string, then it (or an appropriate substitute) is returned.

If headers is a non-empty tuple, headers[0] is a string, and there exists a standardized spelling for header[0] that differs from it, then a new tuple is returned. This tuple has the same elements as headers, except the first element is the standardized spelling for headers[0].

If headers is a sequence, then a new list is considered, where each element is its corresponding element in headers, but mapped as above if a string or tuple. This new list is returned if at least one of its elements differ from their corrsponding element in headers.

If headers is a mapping, then a new dict is considered, where the key in each item is the key of its corresponding item in headers, mapped as above if a string or tuple. The value is taken from the corresponding item. If the keys of multiple items in headers map to the same key after being standardized, then the value for the resulting item is undefined. The new dict is returned if at least one of its items has a key that differs from that of their corresponding item in headers, or if the keys of multiple items in headers map to the same key after being standardized.

In all other cases headers is returned unaltered.


Module contents