There was some strange output during "guix-build acl" (which, again, needed
bash):

...
[76] $ getfacl --omit-header --no-effective d e f g -- failed
user::rwx                             == user::rwx
group::r-x                            != user:root:rwx
other::r-x                            != user:bin:rwx
                                      != group::r-x
user::rwx                             != mask::rwx
group::r-x                            != other::r-x
other::r-x                            != default:user::rwx
                                      != default:user:bin:rwx
user::rw-                             != default:group::r-x
group::r--                            != default:mask::rwx
other::r--                            != default:other::r-x
                                      == 
user::rw-                             != user::rwx
group::r--                            != user:root:rwx
other::r--                            != user:bin:rwx
                                      != group::r-x
~                                     != mask::rwx
~                                     != other::r-x
~                                     != default:user::rwx
~                                     != default:user:bin:rwx
~                                     != default:group::r-x
~                                     != default:mask::rwx
~                                     != default:other::r-x
~                                     != 
~                                     != user::rw-
~                                     != user:root:rwx
~                                     != user:bin:rwx
~                                     != group::r-x
~                                     != mask::rw-
~                                     != other::r--
~                                     != 
~                                     != user::rw-
~                                     != user:root:rwx
~                                     != user:bin:rwx
~                                     != group::r-x
~                                     != mask::rw-
~                                     != other::r--
~                                     != 
[116] $ rm f g -- ok
[117] $ rmdir d e -- ok
[118] $ cd .. -- ok
[119] $ rm -rf d -- ok
24 commands (16 passed, 8 failed)
make: *** [setfacl-X.test] Error 8
make: Leaving directory `/tmp/nix-build-acl-2.2.51.drv-0/acl-2.2.51/test'
starting phase `install'

It looks as if the "make check" phase failed. Should the build not be
interrupted then?

Andreas