Do not overwrite CPPFLAGS

[mbiebl]

Use AM_CPPFLAGS instead of ovewriting CPPFLAGS. CPPFLAGS is a user variable reserved for local modifications. See https://www.gnu.org/software/automake/manual/html_node/Flag-Variables-Ordering.html

[StorageGhoul]

Can one of the admins verify this patch?

[mbiebl]

In Debian we pass certain hardening build flags to all packages and I was wondering why that failed for udisks: https://salsa.debian.org/utopia-team/udisks2/-/jobs/5927192

Turns out that the udisks build system uses CPPFLAGS whereas it should use AM_CPPFLAGS

[vojtechtrefny]

Jenkins, ok to test.