configure: WARNING: texi2dvi: program not found: building pdf version of manual will not work
configure: WARNING: ${top_srcdir}/build-aux/missing indent does not appear to be GNU indent; 'make indent' may not function properly
main.c: In function ‘check_options’:
main.c:347:14: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
   if ((slash = strrchr(M4, '/')) != NULL) {
              ^
main.c: In function ‘check_options’:
main.c:347:14: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
   if ((slash = strrchr(M4, '/')) != NULL) {
              ^
ar: `u' modifier ignored since `D' is the default (see `U')
ERROR: flex/2.6.4: Error in package() method, line 75
	os.unlink(os.path.join(self.package_folder, "lib", "libfl_pic.la"))
	FileNotFoundError: [Errno 2] No such file or directory: '/home/conan/w/cci_PR-3873/.conan/data/flex/2.6.4/_/_/package/d4e2c4fda75c443daaf5f26224d0044231fb93f3/lib/libfl_pic.la'