Return an input port containing the data at URI, and the expected number of bytes available or #f. If TEXT? is true, the data at URI is considered to be textual. Follow any HTTP redirection. When BUFFERED? is #f, return an unbuffered port, suitable for use in `filtered-port'. HEADERS is an alist of extra HTTP headers.

When KEEP-ALIVE? is true, the connection is marked as 'keep-alive' and PORT is not closed upon completion.

When VERIFY-CERTIFICATE? is true, verify HTTPS server certificates.

TIMEOUT specifies the timeout in seconds for connection establishment; when TIMEOUT is #f, connection establishment never times out.

Write information about redirects to LOG-PORT.

Raise an '&http-get-error' condition if downloading fails.

Like 'http-fetch', return an input port, but cache its contents in ~/.cache/guix. The cache remains valid for TTL seconds.

Call WRITE-CACHE with the HTTP input port and the cache output port to write the data to cache. Call CACHE-MISS with URI just before fetching data from URI.

HEADERS is an alist of extra HTTP headers, to which cache-related headers are added automatically as appropriate.

TIMEOUT specifies the timeout in seconds for connection establishment.

Write information about redirects to LOG-PORT.

Return the translation of the package description or synopsis MSGID.

Given the CABAL-SEXP produced by 'read-cabal', evaluate all conditionals and return a 'cabal-package' object. The values of all tests can be overwritten by specifying the desired value in ENV. ENV must be an alist. The accepted keys are: "os", "arch", "impl" and a name of a flag. The value associated with a flag has to be either "true" or "false". The value associated with other keys has to conform to the Cabal file format definition.