bug#25691: locale generation is broken

[ng0]

On two systems, even after make clean and ./bootstrap again I ran into
this at the end of guix system build foo.scm:


   /gnu/store/w8xrphf4r4wwc3q7wy975b9mc6fsf7nf-python2-pycairo-1.10.0.drv
   /gnu/store/a13pjhfrjldnp2zkr0qkbm70llmrdc41-wicd-1.7.4.drv
   /gnu/store/nj0bh3x8fzhvfdpbzz7facv86viq06nv-activate-service.drv
   /gnu/store/07l0msymh88c9ngly78w0azymrvwy16k-module-import.drv
   /gnu/store/6yv8z6hzzy87l9c8spgjbxy2mfv5r8fl-module-import-compiled.drv
   /gnu/store/l63rv3nij0314g17yb856zcss222ml1n-firmware.drv
   /gnu/store/2ymzg5nxsajg8jqxp65dip3h4lkrbslq-activate-service.drv
   /gnu/store/0ymys3hc3d3f1wwgsywnirghcd2qa8hg-activate-service.drv
   /gnu/store/pr76b48cy0jd50p343svw9jgnq86jbf5-module-import-compiled.drv
   /gnu/store/rg5gfw2c1qjxx2cxyzkycs1gna428qh2-module-import.drv
   /gnu/store/1slls8g5j9xh4498jdyipl16y9p5p0i3-activate.drv
   /gnu/store/7gmmqal7fryccg6sim6vlr594qn50j1b-shepherd-0.3.2.drv
   /gnu/store/4q2wfywxdv2f6ym4qq3ipm57a5xjapgm-boot.drv
   /gnu/store/4q5b40jrg5l23f40kmds98jck8vwr4z3-base-initrd.drv
   /gnu/store/lh3w7dgkv5hiy5cmkp5is9bn8gjnyy3i-etc.drv
cannot open locale definition file `en_US': No such file or directory
building locale 'en_US.UTF-8'...
builder for `/gnu/store/dxxnb2m02v6yxx9psddb6z92a947x77y-locale-2.22.drv' 
failed with exit code 1
cannot build derivation 
`/gnu/store/masykw8yxzsq6mkccsdlxlaq9vxwxg3n-locale-multiple-versions.drv': 1 
dependencies couldn't be built
cannot build derivation 
`/gnu/store/bzwnyayh276ln6lvynr93v57r16id6iq-system.drv': 1 dependencies 
couldn't be built
guix system: error: build failed: build of 
`/gnu/store/bzwnyayh276ln6lvynr93v57r16id6iq-system.drv' failed


I am using en_US.UTF-8 since forever and it always worked. The system
checkouts are on HEAD.
-- 
ng0 -- https://www.inventati.org/patternsinthechaos/