During an exp-run for llvm 13 (see bug 258209), it turned out that archivers/upx fails to build with clang 13 :
p_wcle.cpp:739:27: error: variable 'n' set but not used [-Werror,-Wunused-but-set-variable]
1 error generated.
This is because clang 13 now has a -Wunused-but-set-variable warning similar to gcc's, and it is enabled under -Wall.
The p_wcle.cpp file has two instances where the 'n' variable is used for debugging purposes, but the first instance is marked with UNUSED(n). The second is not, triggering this warning.
Created attachment 227794 [details]
Fix unused-but-set variable in upx