Cargo build system: Lock file cannot be updated

Cargo build system: Lock file cannot be updated

[Francisco Gómez García]

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I’m relatively new to Guix – been casually trying it out from time to time this last 2 years, but never used it beyond installing Emacs and a few extra packages. I decided, for some reason, to learn to create packages by using the new Cargo build system for crates. I ended up going for `ansi-term` (https://crates.io/crates/ansi_term). After managing to get a working script (not hard at all, if you know how!), I attempt to build the package, and after a few seconds the following log appears and the process aborts:

  starting phase `build'
  error: the lock file needs to be updated but --locked was passed to prevent this
  phase `build' failed after 0.0 seconds

I can assume it’s attempting to modify the current crate's Cargo.lock, but obviously is unable to do so. Is this some sort of bug on the build system, or is there any parameter which the script is missing?

My .scm has been attached to the mail, for those who want to take a look. Thank you in advance!


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(define-module (rust-ansi-term)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix build-system cargo)
  #:use-module (guix licenses))

(define-public rust-ansi-term
  (package
    (name "rust-ansi-term")
    (version "0.9.0")
    (source
      (origin
        (method url-fetch)
        (uri (crate-uri "ansi_term" version))
        (file-name
          (string-append name "-" version ".tar.gz"))
        (sha256
          (base32
            "1xif1bh938qpfc3d0f9xgidibpm65xix11w9gszwqnia00q7rb13"))))
    (build-system cargo-build-system)
    (home-page
      "https://github.com/ogham/rust-ansi-term")
    (synopsis
      "Library for ANSI terminal colours and styles (bold, underline)")
    (description
      "Library for ANSI terminal colours and styles (bold, underline)")
    (license expat)))

Re: Cargo build system: Lock file cannot be updated

[David Craven]

> I can assume it’s attempting to modify the current crate's Cargo.lock,
> but obviously is unable to do so. Is this some sort of bug on the build
> system, or is there any parameter which the script is missing?

Ansi term is a rust library. Because of that it does not have a
Cargo.lock file. This means that cargo needs to perform it's
dependency resolution algorithm to determine which dependencies are
needed and which versions. This doesn't work because cargo requires
network connectivity to download the crates.io registry. To prevent
this we pass the --frozen flag to cargo build. This is a bit annoying
in this particular case because there are no dependencies. What you
are experiencing is a known deficiency in the cargo-build-system [0],
the relevant excerpt copied below for reference.

* Cargo build system should not do anything if there isn't a
Cargo.lock file except copy the source to out.

Contributions are welcome!

[0] http://lists.gnu.org/archive/html/guix-devel/2016-12/msg00454.html