Compilation error on Windows using Mingw

[CoffeeStraw]

Hi,
I'm trying to build using mingw. I'm using Python 3.9.1, Meson 0.56.2, Ninja 1.10.2 and Mingw version 8.1.0 (architecture x86_64).

Everything seems to go just fine until I get this error:

[148/205] Compiling C object libass/libass.dll.p/ass_bitmap.c.obj
FAILED: libass/libass.dll.p/ass_bitmap.c.obj
"gcc" "-Ilibass\libass.dll.p" "-Ilibass" "-I..\libass" "-I." "-I.." "-I..\subprojects\freetype2\include" "-Isubprojects\fribidi" "-I..\subprojects\fribidi" "-Isubprojects\fribidi\lib" "-I..\subprojects\fribidi\lib" "-Isubprojects\fribidi\gen.tab" "-I..\subprojects\fribidi\gen.tab" "-Isubprojects\harfbuzz\src" "-I..\subprojects\harfbuzz\src" "-fdiagnostics-color=always" "-pipe" "-D_FILE_OFFSET_BITS=64" "-Wall" "-Winvalid-pch" "-Wextra" "-std=c99" "-O2" "-g" "-Wno-sign-compare" "-Wno-unused-parameter" "-Werror-implicit-function-declaration" "-Wstrict-prototypes" "-Wpointer-arith" "-Wredundant-decls" "-Wno-missing-field-initializers" "" -MD -MQ libass/libass.dll.p/ass_bitmap.c.obj -MF "libass\libass.dll.p\ass_bitmap.c.obj.d" -o libass/libass.dll.p/ass_bitmap.c.obj "-c" ../libass/ass_bitmap.c
gcc: error: : No such file or directory
[157/205] Compiling C++ object subprojects/harfbuzz/src/libharfbuzz-0.dll.p/hb-ot-layout.cc.obj
ninja: build stopped: subcommand failed.

Before this I just got warnings. I already checked for imports existance and it seems like nothing is missing. Also ../libass/ass_bitmap.c seems to be reachable. Hopefully you can solve it!