Efraim Flashner <efraim@flashner.co.il> writes:

> I have a package which currently depends on gfortran-5, although
> gfortran-5 doesn't build on core-updates.
>
> efraimf@penguin2:~/workspace/guix-core-updates$ ./pre-inst-env guix build --no-grafts -e '(@@ (gnu packages gcc) gfortran-5)'
> substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
> The following derivation will be built:
>    /gnu/store/frqb5p2vdk8qcjwbny1s6mlak344a0gx-gfortran-5.5.0.drv
> building /gnu/store/frqb5p2vdk8qcjwbny1s6mlak344a0gx-gfortran-5.5.0.drv...
> Backtrace:
> In ice-9/eval.scm:
>    217:50 19 (lp (#<procedure 7fffee835f40 at ice-9/eval.scm:282:?> ?))
>    217:50 18 (lp (#<procedure 7fffee835f20 at ice-9/eval.scm:282:?> ?))
>    217:50 17 (lp (#<procedure 7fffee835f00 at ice-9/eval.scm:282:?> ?))
>    217:50 16 (lp (#<procedure 7fffee835ee0 at ice-9/eval.scm:282:?> ?))
>    217:50 15 (lp (#<procedure 7fffee835e80 at ice-9/eval.scm:649:?> ?))
>    217:50 14 (lp (#<procedure 7fffee835e60 at ice-9/eval.scm:282:?> ?))
>    217:50 13 (lp (#<procedure 7fffee835e00 at ice-9/eval.scm:649:?> ?))
>    217:50 12 (lp (#<procedure 7fffee835de0 at ice-9/eval.scm:282:?> ?))
>    217:50 11 (lp (#<procedure 7fffee835dc0 at ice-9/eval.scm:282:?> ?))
>    217:50 10 (lp (#<procedure 7fffee835da0 at ice-9/eval.scm:282:?> ?))
>    217:50  9 (lp (#<procedure 7fffee835b20 at ice-9/eval.scm:649:?> ?))
>    217:50  8 (lp (#<procedure 7fffee835b00 at ice-9/eval.scm:282:?> ?))
>    217:50  7 (lp (#<procedure 7fffee835ae0 at ice-9/eval.scm:282:?> ?))
>    217:50  6 (lp (#<procedure 7fffee835ac0 at ice-9/eval.scm:282:?> ?))
>    217:33  5 (lp (#<procedure 7fffee7fe9c0 at ice-9/eval.scm:196:?> ?))
>    196:43  4 (_ #f)
>    196:35  3 (_ #f)
>    202:27  2 (_ #f)
>    223:20  1 (proc #<directory (guile-user) 7fffefbadf00>)
>    In unknown file:
>            0 (%resolve-variable (7 . cut) #<directory (guile-user) 7?>)
>
> ERROR: In procedure %resolve-variable:
> Unbound variable: cut

Fixed in 587398d2a82e0b5966a6827d36a1f1d115181b11, thanks!