bug#35034: One libgit2 derivation fails on armhf, another succeeds

[Mark H Weaver]

The 'guile2.0-git-0.2.0' package fails to build on hydra.gnu.org,
because its dependency 'libgit2' fails to build:

  https://hydra.gnu.org/build/3429713#tabs-buildsteps

However, there's another 'libgit2' derivation in the same evaluation,
which succeeds:

  https://hydra.gnu.org/eval/110449?filter=libgit2

Looking at the source for 'guile2.0-git', defined in
gnu/packages/guile.scm, it appears to use the standard 'libgit2'
package, unless 'package-for-guile-2.0' is somehow modifying the
'libgit2' derivation.

Any idea what's going on here?

       Mark