bug#27943: tar complains about too-long names (guix release)

[Danny Milosavljevic]

guix $ make release
... || chmod -R a+r "guix-0.13.0.1849-cf189-dirty"
tardir=guix-0.13.0.1849-cf189-dirty && ${TAR-tar} chof - "$tardir" | 
GZIP=--best gzip -c >guix-0.13.0.1849-cf189-dirty.tar.gz
gzip: warning: GZIP environment variable is deprecated; use an alias or script
tar: 
guix-0.13.0.1849-cf189-dirty/gnu/packages/patches/ghc-dont-pass-linker-flags-via-response-files.patch:
 file name is too long (max 99); not dumped
tar: 
guix-0.13.0.1849-cf189-dirty/gnu/packages/patches/libevent-2.0-evbuffer-add-use-last-with-datap.patch:
 file name is too long (max 99); not dumped
tar: 
guix-0.13.0.1849-cf189-dirty/gnu/packages/patches/python-genshi-stripping-of-unsafe-script-tags.patch:
 file name is too long (max 99); not dumped
tar: 
guix-0.13.0.1849-cf189-dirty/gnu/packages/patches/python2-pygobject-2-gi-info-type-error-domain.patch:
 file name is too long (max 99); not dumped
tar: 
guix-0.13.0.1849-cf189-dirty/gnu/packages/patches/t1lib-CVE-2011-1552+CVE-2011-1553+CVE-2011-1554.patch:
 file name is too long (max 99); not dumped
tar: Exiting with failure status due to previous errors
make[1]: Leaving directory '/home/dannym/src/guix-master/guix'