> commit cce654fabdf09cac7d18f9bad842ba8445aa022c
> Author: Julien Lepiller <address@hidden>
> Date:   Mon Dec 17 21:05:35 2018 +0100
> 
>     import: Update opam importer.
>     
>     * guix/import/opam.scm: Update importer for opam 2.
>     * tests/opam.scm: Update tests for the opam 2 importer.
> ---
>  guix/import/opam.scm | 305 ++++++++++++++++++++++++++++-----------------------
>  po/guix/POTFILES.in  |   1 +
>  tests/opam.scm       | 225 +++++++++++++++++++++++++------------
>  3 files changed, 321 insertions(+), 210 deletions(-)
> 
> diff --git a/guix/import/opam.scm b/guix/import/opam.scm
> index f252bdc..c42a5d7 100644
> --- a/guix/import/opam.scm
> +++ b/guix/import/opam.scm
> @@ -17,132 +17,108 @@
>  ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
>  
>  (define-module (guix import opam)
> +  #:use-module (ice-9 ftw)
>    #:use-module (ice-9 match)
> -  #:use-module (ice-9 vlist)
> +  #:use-module (ice-9 peg)

This commit breaks Guix compatibility with Guile 2.0:

  $ guix build -K --with-commit=guile2.0-guix=cce654fabf guile2.0-guix
<...snip...>
  LOAD     guix/import/opam.scm Backtrace:
In ice-9/r4rs.scm:
  90: 19 [dynamic-wind #<procedure d2f450 at ice-9/eval.scm:416:20 ()> ...]
In ice-9/eval.scm:
 432: 18 [eval # #]
 432: 17 [eval # #]
 481: 16 [lp (#<fluid 5>) (#<output: void 4ba000>)]
In ice-9/boot-9.scm:
2900: 15 [resolve-interface (guix import opam) #:select ...]
2825: 14 [#<procedure 651ac0 at ice-9/boot-9.scm:2813:4 (name #:optional autoload version #:key ensure)> # ...]
In ice-9/r4rs.scm:
  90: 13 [dynamic-wind #<procedure 14fbd80 at ice-9/eval.scm:416:20 ()> ...]
In ice-9/boot-9.scm:
3101: 12 [try-module-autoload (guix import opam) #f]
2412: 11 [save-module-excursion #<procedure 14fba20 at ice-9/boot-9.scm:3102:17 ()>]
3121: 10 [#<procedure 14fba20 at ice-9/boot-9.scm:3102:17 ()>]
In unknown file:
   ?: 9 [primitive-load-path "guix/import/opam" ...]
In ice-9/eval.scm:
 505: 8 [#<procedure 59e5e0 at ice-9/eval.scm:499:4 (exp)> (define-module # # ...)]
In ice-9/psyntax.scm:
1107: 7 [expand-top-sequence ((define-module # # # ...)) () ((top)) ...]
 990: 6 [scan ((define-module (guix import opam) #:use-module ...)) () ...]
 279: 5 [scan ((#(syntax-object let # ...) (#) (# #) ...)) () ...]
In ice-9/eval.scm:
 411: 4 [eval # ()]
In ice-9/boot-9.scm:
2987: 3 [define-module* (guix import opam) #:filename ...]
2962: 2 [resolve-imports (((ice-9 ftw)) ((ice-9 match)) ((ice-9 peg)) ...)]
2903: 1 [resolve-interface (ice-9 peg) #:select ...]
In unknown file:
   ?: 0 [scm-error misc-error #f "~A ~S" ("no code for module" (ice-9 peg)) #f]

ERROR: In procedure scm-error:
ERROR: no code for module (ice-9 peg)
make[2]: *** [Makefile:5572: make-go] Error 1
make[2]: Leaving directory '/tmp/guix-build-guile2.0-guix-git.cce654f.drv-0/source'
make[1]: *** [Makefile:4653: all-recursive] Error 1
make[1]: Leaving directory '/tmp/guix-build-guile2.0-guix-git.cce654f.drv-0/source'
make: *** [Makefile:3269: all] Error 2


I'm hesitant to suggest that we just update our requirements to Guile
2.2 (though I know Ludovic wants to do that eventually), since I think
that would just makes things that much harder for anyone who wants to
build Guix from source on a foreign distro.  Debian stable does not
have Guile 2.2 (it's at Guile 2.0.13).

OTOH, I'm don't now how to keep this code working on Guile 2.0.13.

`~Eric