Overriding a package’s source with ‘guix build’

[ludo@gnu.org (Ludovic Courtès)]

Commit 7f3673f adds a ‘--with-source’ option to ‘guix build’:

‘--with-source=SOURCE’
     Use SOURCE as the source of the corresponding package.  SOURCE must
     be a file name or a URL, as for ‘guix download’ (*note Invoking
     guix download::).

     The “corresponding package” is taken to be one specified on the
     command line whose name matches the base of SOURCE—e.g., if SOURCE
     is ‘/src/guile-2.0.10.tar.gz’, the corresponding package is
     ‘guile’.  Likewise, the version string is inferred from SOURCE; in
     the previous example, it’s ‘2.0.10’.

     This option allows users to try out versions of packages other than
     the one provided by the distribution.  The example below downloads
     ‘ed-1.7.tar.gz’ from a GNU mirror and uses that as the source for
     the ‘ed’ package:

          guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz

     As a developer, ‘--with-source’ makes it easy to test release
     candidates:

          guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz


Pretty cool no?  :-)

Comments welcome!

Ludo’.