fatal errors when compiling.

[M0j0-Jr]

[ 1%] Building C object CMakeFiles/regex.dir/regex/regcomp.c.o
[ 2%] Building C object CMakeFiles/regex.dir/regex/regerror.c.o
[ 3%] Building C object CMakeFiles/regex.dir/regex/regexec.c.o
[ 4%] Building C object CMakeFiles/regex.dir/regex/regfree.c.o
[ 5%] Linking C static library libregex.a
[ 5%] Built target regex
[ 6%] Generating vi/extern.h
[ 6%] Generating cl/extern.h
[ 7%] Generating common/extern.h
[ 8%] Generating common/options_def.h
[ 8%] Generating ex/ex_def.h
[ 9%] Generating ex/extern.h
[ 10%] Generating ex/version.h
[ 11%] Building C object CMakeFiles/nvi.dir/cl/cl_funcs.c.o
[ 12%] Building C object CMakeFiles/nvi.dir/cl/cl_main.c.o
[ 13%] Building C object CMakeFiles/nvi.dir/cl/cl_read.c.o
[ 13%] Building C object CMakeFiles/nvi.dir/cl/cl_screen.c.o
[ 14%] Building C object CMakeFiles/nvi.dir/cl/cl_term.c.o
[ 15%] Building C object CMakeFiles/nvi.dir/common/conv.c.o
[ 16%] Building C object CMakeFiles/nvi.dir/common/cut.c.o
[ 17%] Building C object CMakeFiles/nvi.dir/common/delete.c.o
[ 18%] Building C object CMakeFiles/nvi.dir/common/encoding.c.o
[ 18%] Building C object CMakeFiles/nvi.dir/common/exf.c.o
[ 19%] Building C object CMakeFiles/nvi.dir/common/key.c.o
In file included from /home/rvw/nvi2/common/common.h:78,
from /home/rvw/nvi2/common/key.c:26:
/home/rvw/nvi2/common/key.c: In function ‘v_key_name’:
/home/rvw/nvi2/common/key.h:25:29: error: implicit declaration of function ‘wcwidth’ [-Wimplicit-function-declaration]
25 | #define XCHAR_WIDTH(sp, ch) wcwidth(ch)
| ^~~~~~~
/home/rvw/nvi2/common/key.h:26:30: note: in expansion of macro ‘XCHAR_WIDTH’
26 | #define CAN_PRINT(sp, ch) (XCHAR_WIDTH(sp, ch) > 0)
| ^~~~~~~~~~~
/home/rvw/nvi2/common/key.c:269:13: note: in expansion of macro ‘CAN_PRINT’
269 | if (CAN_PRINT(sp, ach))
| ^~~~~~~~~
make[2]: *** [CMakeFiles/nvi.dir/build.make:353: CMakeFiles/nvi.dir/common/key.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:90: CMakeFiles/nvi.dir/all] Error 2
make: *** [Makefile:91: all] Error 2

[lichray]

Please provide OS, version. And search in the base system headers, to see which header provides wcwidth under which condition.