Call (PROC OBJECT RESULT) for each variable exported by one of MODULES, using INIT as the initial value of RESULT. It is guaranteed to never traverse the same object twice.

Return the list of package modules found in PATH, a list of directories to search. Entries in PATH can be directory names (strings) or (DIRECTORY . SUB-DIRECTORY) pairs, in which case modules are searched for beneath SUB-DIRECTORY. Modules are listed in the order they appear on the path.

Return the list of Scheme modules available under DIRECTORY. Optionally, narrow the search to SUB-DIRECTORY.

WARN is called when a module could not be loaded. It is passed the module name and the exception key and arguments.

Return the list of module names found under SUB-DIRECTORY in DIRECTORY. This is a source-only variant that does not try to load files.

Return the list of Scheme files found under DIRECTORY, recursively. The returned list is sorted in alphabetical order. Return the empty list if DIRECTORY is not accessible.

Write to IMAGE a layerer Docker image archive containing the given PATHS. PREFIX must be a store path that is a prefix of any store paths in PATHS. REPOSITORY is a descriptive name that will show up in "REPOSITORY" column of the output of "docker images".

When DATABASE is true, copy it to /var/guix/db in the image and create /var/guix/gcroots and friends.

When ENTRY-POINT is true, it must be a list of strings; it is stored as the entry point in the Docker image JSON structure.

ENVIRONMENT must be a list of name/value pairs. It specifies the environment variables that must be defined in the resulting image.

EXTRA-FILES must be a list of directives for 'evaluate-populate-directive' describing non-store files that must be created in the image.

TRANSFORMATIONS must be a list of (OLD -> NEW) tuples describing how to transform the PATHS. Any path in PATHS that begins with OLD will be rewritten in the Docker image so that it begins with NEW instead. If a path is a non-empty directory, then its contents will be recursively added, as well.

SYSTEM is a GNU triplet (or prefix thereof) of the system the binaries in PATHS are for; it is used to produce metadata in the image. Use COMPRESSOR, a command such as '("gzip" "-9n"), to compress IMAGE. Use CREATION-TIME, a SRFI-19 time-utc object, as the creation time in metadata.

When MAX-LAYERS is not false build layered image, providing a Docker image with store paths split in their own layers to improve sharing between images.

ROOT-SYSTEM is a directory with a provisioned root file system, which will be added to image as a layer.

Return a fixed-output derivation that fetches data from URL (a string, or a list of strings denoting alternate URLs), which is expected to have hash HASH of type HASH-ALGO (a symbol). By default, the file name is the base name of URL; optionally, NAME can specify a different file name. When EXECUTABLE? is true, make the downloaded file executable.

When one of the URL starts with mirror://, then its host part is interpreted as the name of a mirror scheme, taken from %MIRROR-FILE.

Alternatively, when URL starts with file://, return the corresponding file name in the store.

Like 'url-fetch', but make the downloaded file executable.

Similar to 'url-fetch' but unpack the zip file at URL in a directory of its own. This helper makes it easier to deal with "zip bombs".

Similar to 'url-fetch' but unpack the file from URL in a directory of its own. This helper makes it easier to deal with "tar bombs".

Download from URL to STORE, either under NAME or URL's basename if omitted. Write progress reports to LOG. RECURSIVE? has the same effect as the same-named parameter of 'add-to-store'. VERIFY-CERTIFICATE? determines whether or not to validate HTTPS server certificates.