msys rust (unofficial) test (hacky)

README.md

first get cygwin rust (unofficial) from here (we will reconfigure it for linking against msys DLL instead of cygwin)

make sure you have gcc install for msys environment and run these in the MINGW64 terminal

Hello world:

export PATH=/path/to/cygwin-rust/bin:$PATH

cargo new --bin hellohi && cd hellohi
# must be called x86_64-pc-cygwin.json! (i.e. don't change the file name!)
rustc -Z unstable-options --target=x86_64-pc-cygwin --print target-spec-json > x86_64-pc-cygwin.json
patch -p1 -i path/to/x86_64-pc-cygwin.json.diff
# must place the json under the current directory!
cargo build --target=x86_64-pc-cygwin.json
# don't get tricked by the target name, it's now linked against msys-2.0.dll!
ldd ./target/x86_64-pc-cygwin/debug/hellohi.exe
./target/x86_64-pc-cygwin/debug/hellohi.exe

should give:

           ntdll.dll => /c/WINDOWS/SYSTEM32/ntdll.dll (0x7ff9535d0000)
           KERNEL32.DLL => /c/WINDOWS/System32/KERNEL32.DLL (0x7ff9530c0000)
           KERNELBASE.dll => /c/WINDOWS/System32/KERNELBASE.dll (0x7ff950ad0000)
           msys-2.0.dll => /usr/bin/msys-2.0.dll (0x180040000)

Hello, world!

x86_64-pc-cygwin.json.diff

--- a/x86_64-pc-cygwin.json     2024-05-05 13:19:53.530699500 +0800
+++ b/x86_64-pc-cygwin.json          2024-05-05 13:17:47.610426400 +0800
@@ -12,27 +12,26 @@
   "emit-debug-gdb-scripts": false,
   "exe-suffix": ".exe",
   "function-sections": false,
-  "is-builtin": true,
   "is-like-windows": true,
   "late-link-args": {
     "gcc": [
-      "-lcygwin",
+      "-lmsys-2.0",
       "-lgcc",
-      "-lcygwin",
+      "-lmsys-2.0",
       "-luser32",
       "-lkernel32"
     ],
     "ld": [
-      "-lcygwin",
+      "-lmsys-2.0",
       "-lgcc",
-      "-lcygwin",
+      "-lmsys-2.0",
       "-luser32",
       "-lkernel32"
     ],
     "ld.lld": [
-      "-lcygwin",
+      "-lmsys-2.0",
       "-lgcc",
-      "-lcygwin",
+      "-lmsys-2.0",
       "-luser32",
       "-lkernel32"
     ]
@@ -62,7 +61,7 @@
       "-l:libpthread.a"
     ]
   },
-  "linker": "x86_64-pc-cygwin-gcc",
+  "linker": "x86_64-pc-msys-gcc",
   "llvm-target": "x86_64-unknown-windows-cygnus",
   "max-atomic-width": 64,
   "os": "cygwin",