[Pkg-rust-maintainers] Bug#933757: Firefox-esr FTBFS "failed to open: /sbuild-nonexistent/.cargo/.package-cache"

[Peter Michael Green]

Package: firefox-esr
Version: 60.8.0esr-1
Severity: serious
x-debbugs-cc: pkg-rust-maintainers at alioth-lists.debian.net

While trying to update firefox-esr in raspbian bullseye I ran into a 
"failed to open: /sbuild-nonexistent/.cargo/.package-cache" error. The 
failure also shows up on the reproducible builds site for i386 and arm64 
so it's not raspbian specific. I suspect it is only reproducible in 
builds with a nonexistent homedir (as is the standard sbuild configuration).

I would guess this was triggered by the recent upload of a new version 
of cargo.

> error: failed to acquire package cache lock
>
> Caused by:
>    failed to open: /nonexistent/first-build/.cargo/.package-cache
>
> Caused by:
>    Permission denied (os error 13)
> /usr/bin/g++ -o buddhcal.o -c -I/build/1st/firefox-esr-60.8.0esr/build-browser/dist/system_wrappers -include /build/1st/firefox-esr-60.8.0esr/config/gcc_hidden.h -DNDEBUG=1 -DTRIMMED=1 -DU_I18N_IMPLEMENTATION -DUCONFIG_NO_TRANSLITERATION -DUCONFIG_NO_REGULAR_EXPRESSIONS -DUCONFIG_NO_LEGACY_CONVERSION -DU_USING_ICU_NAMESPACE=0 -DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1 -DU_CHARSET_IS_UTF8 -DU_HAVE_NL_LANGINFO_CODESET=0 -I/build/1st/firefox-esr-60.8.0esr/config/external/icu/i18n -I/build/1st/firefox-esr-60.8.0esr/build-browser/config/external/icu/i18n -I/build/1st/firefox-esr-60.8.0esr/intl/icu/source/common -I/build/1st/firefox-esr-60.8.0esr/build-browser/dist/include -I/usr/include/nspr -I/usr/include/nss -fPIC -DMOZILLA_CLIENT -include /build/1st/firefox-esr-60.8.0esr/build-browser/mozilla-config.h -Wdate-time -D_FORTIFY_SOURCE=2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wall -Wempty-body -Wignored-qualifiers -Woverloaded-virtual -Wpointer-arith -Wsign-compare -Wtype-limits -Wunreachable-code -Wwrite-strings -Wno-invalid-offsetof -Wc++1z-compat -Wduplicated-cond -Wimplicit-fallthrough -Wno-error=maybe-uninitialized -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wformat -Wformat-overflow=2 -fno-sized-deallocation -fstack-protector-strong -Wformat -Werror=format-security -fno-schedule-insns2 -fno-lifetime-dse -fno-delete-null-pointer-checks -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-exceptions -fno-strict-aliasing -fno-rtti -ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pthread -pipe -g -freorder-blocks -O2 -fomit-frame-pointer -frtti  -MD -MP -MF .deps/buddhcal.o.pp   /build/1st/firefox-esr-60.8.0esr/intl/icu/source/i18n/buddhcal.cpp
> make[6]: *** [/build/1st/firefox-esr-60.8.0esr/config/rules.mk:979: force-cargo-library-build] Error 101
> make[6]: Leaving directory '/build/1st/firefox-esr-60.8.0esr/build-browser/toolkit/library/rust'
> make[5]: *** [/build/1st/firefox-esr-60.8.0esr/config/recurse.mk:73: toolkit/library/rust/target] Error 2
> make[5]: *** Waiting for unfinished jobs....