Hi, On Fri, 22 Jan 2021 at 12:36, Wiktor Żelazny <[email protected]> wrote:
> Would be cool, however for MRAN you also need the snapshot date. Would > it be feasible to extract it from the commit date? There are dates at Extract date from ~/.cache/guix/checkouts/pj... and author date of the commit provided at the time-machine should the good one to provide to MRAN. > CRAN, but for the archived package versions these are “Last modified”. > There is also “Date/Publication:” field in the tarball, but you wouldn’t > trust a tarball with a hash mismatch. About trust and mismatch, I would say: it depends. You can still download the new '[email protected]' served by CRAN with the mismatch and audit by hand. Well, that's another story. > I cannot check it. This approach works, but for some mysterious reason > it also works when I remove the r-foreign-fixed definition and constrain > the manifest to r. Without the definition, I would expect guix to try > building r-foreign from CRAN. I thought that maybe guix treated > [email protected] and [email protected] as exchangeable because of > the same hash, even if the versions and URIs differed, and so did not > try to build [email protected], but used [email protected] from the > store. However, with `guix time-machine … -- build [email protected]`, > I’m getting a different output than for `guix time-machine … -- build > [email protected]`. I tried `guix gc <path to r>` to force the > rebuild, but I got the “still alive” error, even though I had exited the > environment. To rebuild, the easiest is the option "build --check". > I will just trust your expertise on that, and keep your solution. I can > always go back to the inferior if it turns out to fail when I encounter > the hash mismatch problem sometime in the future. As I see it, there are 2 options: _ option 1: write the package definition with the new MRAN source (or with the CRAN source but with the new checksum hash), and a manifest file. Then run $ guix time-machine --commit=d81fb2a \ -- environment -m manifest.scm The trick here is to use "--with-input"; somehow the graph has to be rewritten. At the manifest level, it is something with "transform-package-inputs" _ option 2: use another package transformation: "transformation-package-sources". The new API is simpler with "package-with-source", so the manifest could contain... (packages->manifest (cons (package-with-source r-foreign "https://cran.microsoft.com/snapshot/2020-01-27/";) (map specification->package (list "r" "r-another-package")))) ...But the issue is that "package-with-source" was not so simple at commit d81fb2a time. And the way is "transformation-package-sources" even if I am not convinced it is simpler than create by hand the correct 'r-foreign' package with option 1. > Have a nice weekend, Have a nice week-end too! :-) All the best, simon
