Return an integer representing protocol version MAJOR and MINOR.

Extract from MAGIC, an integer, the protocol major version.

Evaluate EXP, a gexp, on the host at SESSION, an SSH session. Ensure that all the elements EXP refers to are built and deployed to SESSION beforehand. When BUILD-LOCALLY? is true, said dependencies are built locally and sent to the remote store afterwards; otherwise, dependencies are built directly on the remote store.

Write the response corresponding to the evaluation of EXP to PORT, an output port. VERSION is the client's protocol version we are targeting.

Run a machine-usable REPL over ports INPUT and OUTPUT.

The protocol of this REPL is meant to be machine-readable and provides proper support to represent multiple-value returns, exceptions, objects that lack a read syntax, and so on. As such it is more convenient and robust than parsing Guile's REPL prompt.

Generate a RPM lead u8-list that uses NAME-VERSION, the name and version string of the package, and TARGET, a GNU triplet used to derive the target machine type.

Return the u8 list corresponding to the Header section. PAYLOAD-DIGEST is the SHA256 checksum string of the compressed payload. PAYLOAD-DIRECTORY is the directory containing the payload files. PAYLOAD-COMPRESSOR is the name of the compressor used to compress the CPIO payload, such as "none", "gz", "xz" or "zstd".

Align and append the various u8 list components together, and return the result as a bytevector.

Predicate to check if FILE-NAME is a known File Hierarchy Standard (FHS) directory.

Return the u8 list representing a signature header containing the HEADER-SHA256 (a string) and the PAYLOAD-SIZE, which is the combined size of the header and compressed payload.