gcc -pedantic ... -o htop ...
ld: ClockMeter.o:/home/slyfox/dev/git/htop/CRT.h:159:
multiple definition of `backtraceArray'; CheckItem.o:htop/CRT.h:159: first defined here
ld: ClockMeter.o:/home/slyfox/dev/git/htop/CRT.h:153:
multiple definition of `CRT_termType'; CheckItem.o:htop/CRT.h:153: first defined here
On gcc-10 (and gcc-9 -fno-common) build fails as:
gcc-10 will change the default from -fcommon to fno-common: https://gcc.gnu.org/PR85678.
The error also happens if CFLAGS=-fno-common passed explicitly.
Reported-by: Toralf Förster Bug: https://bugs.gentoo.org/706358