https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109926
--- Comment #9 from cqwrteur <unlvsur at live dot com> --- (In reply to Jonathan Wakely from comment #8) > Comment on attachment 55135 [details] > config > > configure:18893: checking fenv.h usability > configure:18893: i586-msdosdjgpp-c++ -c -g -O2 -std=c++11 > -fno-exceptions conftest.cpp >&5 > configure:18893: $? = 0 > configure:18893: result: yes > configure:18893: checking fenv.h presence > configure:18893: i586-msdosdjgpp-c++ -E conftest.cpp > configure:18893: $? = 0 > configure:18893: result: yes > configure:18893: checking for fenv.h > configure:18893: result: yes > > This means configure is finding fenv.h in your sysroot. fenv.h is in libstdc++. not in libc. djgpp libc does not provide fenv.h
