I've been trying to get otiai10/gosseract (Go package for Tesseract C++ library) working on Windows without success. As a requirement, gosseract requires the installation of "tesseract-ocr, including library and headers".
The Tesseract Windows compiling documentation mentions the usage of SW and Vcpkg, which to my understanding relies on MSVC and is hence not compatible with Go.
The documentation also mentions the existence of Cygwin packages. I have tried leveraging them by installing tesseract-ocr (5.2.0-1), tesseract-ocr-devel (5.2.0-1), tesseract-ocr-eng (5.00-1) as well as mingw64-x86_64-gcc-g++ and mingw64-x86_64-gcc-core after which I defined the following environment variables:
CGO_CFLAGS=-IC:\cygwin64\usr\include
CGO_CPPFLAGS=-IC:\cygwin64\usr\include
CGO_LDFLAGS=-LC:\cygwin64\lib
PATH=C:\cygwin64\bin;...
CC=C:\cygwin64\bin\x86_64-w64-mingw32-gcc.exe
CXX=C:\cygwin64\bin\x86_64-w64-mingw32-g++.exe
However, trying to compile (through GoLand) an example project (otiai10/ocrserver) still results in linker errors:
GOROOT=C:\Users\REDACTED\go\go1.18rc1 #gosetup
GOPATH=C:\Users\REDACTED\go #gosetup
C:\Users\REDACTED\go\go1.18rc1\bin\go.exe build -o C:\Users\REDACTED\AppData\Local\Temp\GoLand\___go_build_github_com_otiai10_ocrserver.exe github.com/otiai10/ocrserver #gosetup
# github.com/otiai10/gosseract/v2
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: $WORK\b133\_x003.o: in function `tesseract::TessBaseAPI::Init(char const*, char const*)':
/cygdrive/c/Users/REDACTED/go/pkg/mod/github.com/otiai10/gosseract/v2@v2.3.1/C:/cygwin64/usr/include/tesseract/baseapi.h:215: undefined reference to `tesseract::TessBaseAPI::Init(char const*, char const*, tesseract::OcrEngineMode, char**, int, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, bool)'
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: /cygdrive/c/Users/REDACTED/go/pkg/mod/github.com/otiai10/gosseract/v2@v2.3.1/C:/cygwin64/usr/include/tesseract/baseapi.h:215: undefined reference to `tesseract::TessBaseAPI::Init(char const*, char const*, tesseract::OcrEngineMode, char**, int, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, bool)'
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: /cygdrive/c/Users/REDACTED/go/pkg/mod/github.com/otiai10/gosseract/v2@v2.3.1/C:/cygwin64/usr/include/tesseract/baseapi.h:215: undefined reference to `tesseract::TessBaseAPI::Init(char const*, char const*, tesseract::OcrEngineMode, char**, int, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const*, bool)'
collect2: error: ld returned 1 exit status
How can one get "tesseract-ocr, including library and headers" properly set up on a Windows machine for CGO compatibility?
> go version
go version go1.17 windows/amd64
> C:\cygwin64\bin\x86_64-w64-mingw32-gcc.exe --version
x86_64-w64-mingw32-gcc (GCC) 11.3.0
> C:\cygwin64\bin\x86_64-w64-mingw32-g++.exe --version
x86_64-w64-mingw32-g++ (GCC) 11.3.0
> C:\cygwin64\bin\x86_64-w64-mingw32-ld.exe --version
GNU ld (GNU Binutils) 2.38