bug#27515: texlive-texmf-minimal is not reproducible

[Danny Milosavljevic]

$ guix build texlive-texmf-minimal --rounds=2

phase `texmf-config' succeeded after 52.0 seconds
output ‘/gnu/store/jfs5fsn011w64jgmpc6chcnqr1agfv6h-texlive-texmf-minimal-2016’ 
of ‘/gnu/store/72z7v217vd976hlhyjrxzmwpqr4nzwh6-texlive-texmf-minimal-2016.drv’ 
differs from 
‘/gnu/store/jfs5fsn011w64jgmpc6chcnqr1agfv6h-texlive-texmf-minimal-2016-check’ 
from previous round
@ build-failed 
/gnu/store/72z7v217vd976hlhyjrxzmwpqr4nzwh6-texlive-texmf-minimal-2016.drv - 1 
output ‘/gnu/store/jfs5fsn011w64jgmpc6chcnqr1agfv6h-texlive-texmf-minimal-2016’ 
of ‘/gnu/store/72z7v217vd976hlhyjrxzmwpqr4nzwh6-texlive-texmf-minimal-2016.drv’ 
differs from 
‘/gnu/store/jfs5fsn011w64jgmpc6chcnqr1agfv6h-texlive-texmf-minimal-2016-check’ 
from previous round
note: keeping build directory `/tmp/guix-build-texlive-texmf-minimal-2016.drv-0'
cannot build derivation 
`/gnu/store/dpnlwahp8gp65s6a2q3808z9dgcx0cxj-texlive-minimal-2016.drv': 1 
dependencies couldn't be built