Comment 10 for bug 1947424

i'm going to add a "me too!" and a real world example. i needed to apply a patch to ansible-core which is in the list of "Packages in bookworm/amd64 which failed to build from source,"[1] despite it being a fairly prominent piece of software. it turns out this is due to a locale issue:
ERROR: Ansible requires the locale encoding to be UTF-8; Detected None.

i can confirm that using `pdebuild --configfile ~/.pbuilderrc-locale` with the contents
export LC_ALL=C.UTF-8
export LANG=C.UTF-8

was not sufficient to build the package. as noted above, `pbuilder-modules` eventually has the final say and resets them to "C". eventually, i gave up trying to find a "right" way to do it and updated the last lines of `/usr/lib/pbuilder/pbuilder-modules` to get the build done.

1. https://tests.reproducible-builds.org/debian/bookworm/amd64/index_FTBFS.html