ccache 4+ starts respecting SOURCE_DATE_EPOCH [1], it will include it
into the hash of the manifest.
SOURCE_DATE_EPOCH will be passed from debhelpers, by extracting last
entry from d/changelog (or current time if there is entries)
And this will make ccache unusable.
Fix this by ignoring SOURCE_DATE_EPOCH, like current ccache version on
CI does (3.7.7)
[1]: 238553a1c4/src/ccache.cpp (L1279)
Since libtsan.a already has them:
ld.lld: error: duplicate symbol: RunningOnValgrind
>>> defined at dynamic_annotations.cc:99 (../contrib/abseil-cpp/absl/base/dynamic_annotations.cc:99)
>>> dynamic_annotations.cc.o:(RunningOnValgrind) in archive contrib/abseil-cpp/absl/base/libabsl_dynamic_annotations.a
>>> defined at tsan_interface_ann.o:(.text+0x15A0) in archive /usr/lib/gcc/x86_64-linux-gnu/10/libtsan.a
ld.lld: error: duplicate symbol: AnnotateMemoryIsInitialized
>>> defined at dynamic_annotations.cc:75 (../contrib/abseil-cpp/absl/base/dynamic_annotations.cc:75)
>>> dynamic_annotations.cc.o:(AnnotateMemoryIsInitialized) in archive contrib/abseil-cpp/absl/base/libabsl_dynamic_annotations.a
>>> defined at tsan_interface_ann.o:(.text+0x1600) in archive /usr/lib/gcc/x86_64-linux-gnu/10/libtsan.a
ld.lld: error: duplicate symbol: AnnotateMemoryIsUnt show initialized
>>> defined at dynamic_annotations.cc:75 (../contrib/abseil-cpp/absl/base/dynamic_annotations.cc:75)
>>> dynamic_annotations.cc.o:(AnnotateMemoryIsUninitialized) in archive contrib/abseil-cpp/absl/base/libabsl_dynamic_annotations.a
>>> defined at tsan_interface_ann.o:(.text+0x1610) in archive /usr/lib/gcc/x86_64-linux-gnu/10/libtsan.a
...
And after this patch I successfully managed to build with thread
sanitizer under gcc.
