Mingw64 / Msys2 - gcc unable to find headers in its own include dir

Question

I recently installed MSYS2 following Steely Wing's answer on this thread: How to install MinGW-w64 and MSYS2?

The final goal is to compile a project on Windows in order to create an executable that I can use with an installer.

But here comes the problem: when I use make, gcc does not find err.h:

src/debug/error_handler.c:2:10: fatal error: err.h: No such file or directory
        2 | #include <err.h>
          |          ^~~~~~~  
compilation terminated.  
make: *** [Makefile:26: imagin] Interrupt

After some searching I found out that it could come from the MinGW's default Include path. Thus following this: http://mingw.org/wiki/IncludePathHOWTO, I created an empty foo.c and executed gcc -v foo.c:

Configured with: ../gcc-9.2.0/configure --prefix=/mingw64 --with-local-prefix=/mingw64/local --build=x86_64-w64-mingw32 --host=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --with-native-system-header-dir=/mingw64/x86_64-w64-mingw32/include --libexecdir=/mingw64/lib --enable-bootstrap --with-arch=x86-64 --with-tune=generic --enable-languages=c,lto,c++,fortran,ada,objc,obj-c++ --enable-shared --enable-static --enable-libatomic --enable-threads=posix --enable-graphite --enable-fully-dynamic-string --enable-libstdcxx-filesystem-ts=yes --enable-libstdcxx-time=yes --disable-libstdcxx-pch --disable-libstdcxx-debug --disable-isl-version-check --enable-lto --enable-libgomp --disable-multilib --enable-checking=release --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --enable-plugin --with-libiconv --with-system-zlib --with-gmp=/mingw64 --with-mpfr=/mingw64 --with-mpc=/mingw64 --with-isl=/mingw64 --with-pkgversion='Rev2, Built by MSYS2 project' --with-bugurl=https://sourceforge.net/projects/msys2 --with-gnu-as --with-gnu-ld
Thread model: posix
gcc version 9.2.0 (Rev2, Built by MSYS2 project) 
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/cc1.exe -quiet -v -iprefix C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/ -D_REENTRANT foo.c -quiet -dumpbase foo.c -mtune=generic -march=x86-64 -auxbase foo -version -o C:\msys64\tmp\ccXlDSUc.s
GNU C17 (Rev2, Built by MSYS2 project) version 9.2.0 (x86_64-w64-mingw32)
    compiled by GNU C version 9.2.0, GMP version 6.1.2, MPFR version 4.0.2, MPC version 1.1.0, isl version isl-0.21-GMP

warning: GMP header version 6.1.2 differs from library version 6.2.0.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring duplicate directory "C:/msys64/mingw64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/9.2.0/include"
ignoring nonexistent directory "C:/building/msys64/mingw64/include"
ignoring nonexistent directory "/mingw64/include"
ignoring duplicate directory "C:/msys64/mingw64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/9.2.0/include-fixed"
ignoring duplicate directory "C:/msys64/mingw64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/include"
ignoring nonexistent directory "C:/building/msys64/mingw64/x86_64-w64-mingw32/include"
#include "..." search starts here:
#include <...> search starts here:
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/include
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../include
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/include-fixed
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/include
End of search list.
GNU C17 (Rev2, Built by MSYS2 project) version 9.2.0 (x86_64-w64-mingw32)
    compiled by GNU C version 9.2.0, GMP version 6.1.2, MPFR version 4.0.2, MPC version 1.1.0, isl version isl-0.21-GMP

warning: GMP header version 6.1.2 differs from library version 6.2.0.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 3bcdf03344e3ad7cb057c2ec82f696e6
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/as.exe -v -o C:\msys64\tmp\cckgYpTe.o C:\msys64\tmp\ccXlDSUc.s
GNU assembler version 2.33.1 (x86_64-w64-mingw32) using BFD version (GNU Binutils) 2.33.1
COMPILER_PATH=C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/;C:/msys64/mingw64/bin/../lib/gcc/;C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/
LIBRARY_PATH=C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/;C:/msys64/mingw64/bin/../lib/gcc/;C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/;C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../lib/;C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/;C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/collect2.exe -plugin C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/liblto_plugin-0.dll -plugin-opt=C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/lto-wrapper.exe -plugin-opt=-fresolution=C:\msys64\tmp\cch1aQIi.res -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmsvcrt -plugin-opt=-pass-through=-lpthread -plugin-opt=-pass-through=-ladvapi32 -plugin-opt=-pass-through=-lshell32 -plugin-opt=-pass-through=-luser32 -plugin-opt=-pass-through=-lkernel32 -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmsvcrt -m i386pep -Bdynamic C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/crtbegin.o -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0 -LC:/msys64/mingw64/bin/../lib/gcc -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../.. C:\msys64\tmp\cckgYpTe.o -lmingw32 -lgcc -lgcc_eh -lmoldname -lmingwex -lmsvcrt -lpthread -ladvapi32 -lshell32 -luser32 -lkernel32 -lmingw32 -lgcc -lgcc_eh -lmoldname -lmingwex -lmsvcrt C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/default-manifest.o C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/crtend.o
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-crt0_c.o): in function `main':
D:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crt0_c.c:18: undefined reference to `WinMain'
collect2.exe: error: ld returned 1 exit status

This is a bit messy but I think the interesting part is there:

#include "..." search starts here:
#include <...> search starts here:
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/include
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../include
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/include-fixed
 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/include

Considering the fact that err.h comes from openssl that I installed using https://packages.msys2.org/package/mingw-w64-x86_64-openssl, openssl folder is included in /mingw64/include. But gcc does not find it.

I tried to use -I/mingw64/include in my CFLAGS, but it did not work. I tried with -I/mingw64/include/openssl and it worked, but now gcc considers errx function as unititialized, as if, before, gcc never went in the openssl folder. I tried to add -L/mingw64/lib but it did not work.

Any help is appreciated, thank's by advance. DO NOT hesitate to ask for any precision I could have miss here.

Welcome to Stack Overflow! Some additional details might be useful, indeed. What code are you trying to compile? And what (full) command do you use for it? A minimal reproducible example would be handy. — jacob
@jacob Thank you! I'm trying to compile a whole project so I won't post the entire code here. Here is the command provided by my Makefile: gcc -o main src/all/my/.c -W -Wall -Werror -std=c99 -Werror -O3 -lm \ `pkg-config --cflags --libs gtk+-3.0` `pkg-config --cflags --libs libtiff-4` \ `pkg-config --cflags --libs libjpeg` `pkg-config --cflags --libs libxml-2.0` \ `pkg-config --cflags --libs libpng` `pkg-config --cflags --libs gexiv2` — Ewaël

Ewaël Ewaël · Accepted Answer · 2020-03-07T15:54:30

After hours of searching I found out that there was no err.h on MSYS2, see https://github.com/cliffordwolf/icestorm/issues/85 and resolved my case by replacing all my errx() function calls following these method https://github.com/cliffordwolf/icestorm/pull/88/commits/9acaac752ac53b51b9b33290394b7811048221fa.

Mingw64 / Msys2 - gcc unable to find headers in its own include dir

1 Answers