Failure building rustc in x86_64-pc-windows-gnu due to missing __imp__fmode

[segevfiner]

error: linking with `gcc` failed: exit code: 1
  |
  = note: "gcc" "-Wl,--enable-long-section-names" "-fno-use-linker-plugin" "-Wl,--nxcompat" "-nostdlib" "-m64" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib\\crt2.o" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib\\rsbegin.o" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps\\rustc-b67a4fe646fd8794.rustc0-833528dbd46ff06c3b1f5154abdef2ed.rs.rcgu.o" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps\\rustc-b67a4fe646fd8794.rustc1-833528dbd46ff06c3b1f5154abdef2ed.rs.rcgu.o" "-o" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps\\rustc-b67a4fe646fd8794.exe" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps\\rustc-b67a4fe646fd8794.crate.allocator.rcgu.o" "-Wl,--gc-sections" "-nodefaultlibs" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\release\\deps" "-L" "...\\.cargo\\registry\\src\\github.com-1ecc6299db9ec823\\dbghelp-sys-0.2.0/x86_64" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\build\\miniz-sys-98d83a845f69b3ab\\out" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\build\\rustc_binaryen-f106436b515711ff\\out/build/lib" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\build\\rustc_binaryen-f106436b515711ff\\out" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\build\\rustc_llvm-9a040fa1f1937a67\\out" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\llvm/lib" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_driver-224d9efe142c632e" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_trans-767a58ff60ff6a03" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_resolve-bcc2d91b756552d1" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_incremental-e93e816231352cc9" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_plugin-8273bd6d564e8657" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_metadata-5537b9a8ab6e6015" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_lint-796681662b9ad8e1" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_passes-9ef6de765e132a7c" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_privacy-2289da126d06c49e" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_llvm-893cdac51017c26f" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_borrowck-ac2009fc1ce58d88" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_mir-d4ce85a1cded4423" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_const_eval-a4e766ec47afde96" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_save_analysis-66d4c41e75392976" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_typeck-4e21db5573af1446" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_platform_intrinsics-f40c4b99b60d15e9" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_allocator-86ef12c8efbcf068" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_trans_utils-8199c3d0e673bb7b" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc-8f435ca07f1a04ff" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib" "-l" "test-8abb197945b79a6a" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_const_math-fa724350247d1ae6" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_back-838b735c189dd798" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "graphviz-42c69c0ff2aacc5b" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "arena-454325a3f2773bc8" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "syntax_ext-7880c41067f1be05" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "proc_macro-f609718c6b927026" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "syntax-3d2aaf6e201abcfe" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_errors-2c007ffe6a847ed7" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "syntax_pos-067e758dda669d03" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_data_structures-50e5e6db2f34c196" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib" "-l" "term-9d9f4c10ffba6dd6" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "serialize-e55b4fb27a4d08bf" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "rustc_cratesio_shim-baed94e463835a87" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-rustc\\x86_64-pc-windows-gnu\\release\\deps" "-l" "fmt_macros-3c2cdca7d2f8dd09" "-L" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib" "-l" "std-b1b09a5d7798628b" "-Wl,-Bstatic" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib\\libcompiler_builtins-69f85297d9318c97.rlib" "-Wl,-Bdynamic" "-l" "advapi32" "-l" "ole32" "-l" "oleaut32" "-l" "psapi" "-l" "shell32" "-l" "ole32" "-l" "uuid" "-l" "stdc++" "-l" "gcc_eh" "-l" "pthread" "-l" "psapi" "-l" "dbghelp" "-l" "kernel32" "-l" "advapi32" "-l" "kernel32" "-l" "advapi32" "-l" "ws2_32" "-l" "userenv" "-l" "shell32" "-lmingwex" "-lmingw32" "-lgcc" "-lmsvcrt" "-luser32" "-lkernel32" "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0-sysroot\\lib\\rustlib\\x86_64-pc-windows-gnu\\lib\\rsend.o"
  = note: rust/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmsvcrt.a(lib64_libmsvcrt_os_a-__p__fmode.o):__p__fmode.c:(.rdata$.refptr.__imp__fmode[.refptr.__imp__fmode]+0x0): undefined reference to `__imp__fmode'
          collect2.exe: error: ld returned 1 exit status


error: aborting due to previous error

error: Could not compile `rustc-main`.

Caused by:
  process didn't exit successfully: `rust\msys64\home\...\rust\build\bootstrap/debug/rustc --crate-name rustc rustc\rustc.rs --error-format json --crate-type bin --emit=dep-info,link -C opt-level=2 --cfg feature="jemalloc" --cfg feature="llvm" --cfg feature="rustc_back" --cfg feature="rustc_driver" -C metadata=b67a4fe646fd8794 -C extra-filename=-b67a4fe646fd8794 --out-dir rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\deps --target x86_64-pc-windows-gnu -L dependency=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\deps -L dependency=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\release\deps --extern rustc_back=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\deps\rustc_back-838b735c189dd798.dll --extern rustc_driver=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\deps\rustc_driver-224d9efe142c632e.dll -L native=...\.cargo\registry\src\github.com-1ecc6299db9ec823\dbghelp-sys-0.2.0/x86_64 -L native=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\build\miniz-sys-98d83a845f69b3ab\out -L native=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\build\rustc_binaryen-f106436b515711ff\out/build/lib -L native=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\build\rustc_binaryen-f106436b515711ff\out -L native=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\stage0-rustc\x86_64-pc-windows-gnu\release\build\rustc_llvm-9a040fa1f1937a67\out -L native=rust\msys64\home\...\rust\build\x86_64-pc-windows-gnu\llvm/lib` (exit code: 101)
thread 'main' panicked at 'command did not execute successfully: "rust\\msys64\\home\\...\\rust\\build\\x86_64-pc-windows-gnu\\stage0/bin\\cargo.exe" "build" "--target" "x86_64-pc-windows-gnu" "-j" "4" "--release" "--features" " jemalloc llvm" "--manifest-path" "rust/msys64/home/.../rust\\src/rustc/Cargo.toml" "--message-format" "json"
expected success, got: exit code: 101', bootstrap\compile.rs:886:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.
failed to run: rust/msys64/home/.../rust/build/bootstrap/debug/bootstrap build --stage 1 src/libtest
Build completed unsuccessfully in 0:00:25

This looks like a bug in msys2 shipped mingw-w64-x86_64-gcc-libs 7.2.0-1, might be caused by this: mirror/mingw-w64@2e64b9e. Or it could be some bad interaction of this with Rust, not sure if Rust is using it's own shipped tools here.

[retep998]

Rust does not use fmode anywhere (nor does LLVM). This is likely a bug in MinGW.

[segevfiner]

Very likely, I think it complains about __p__fmode.c from MinGW libmsvcrt.

[segevfiner]

Using random guess work I added "-lmsvcrt" again to the command line... and it worked... WAT 😖

[retep998]

gcc/ld is an order dependent linker. This means that the order in which libraries are passed to the linker heavily affects whether linking will succeed. MinGW simply changed something that changes the order that Rust has to specify the various MinGW libraries in, so someone will have to investigate what the correct order should be and submit a PR to fix it.

[segevfiner]

I'm aware of that. My bewilderment stems from it looking like libmsvcrt.a is dependent on itself in a way that requires it to be listed twice... Rather than some other library having to come before it on the command line. But maybe it's really some other hack MinGW does that causes this behavior...

MinGW depends on symbols from the ye olde msvcrt.dll that comes with Windows. But I'm not seeing it specified on the linker command line (gcc -v), so where are its symbols added... Since that's where _fmode is defined, at least that's the _fmode I think it'a looking for...

EDIT: Building with RUSTFLAGS="-C link-arg=-lmsvcrt" makes the build pass.