The easiest way to build is to use make.
go build is not sufficient, especially on Windows.
The Windows version with DLL and COM support needs cgo so it requires a C/C++ compiler on the path. I am using Mingw-w64. You can either install Msys2 or just Mingw-w64. The specific version of GCC shouldn't be critical (but not too ancient). I would recommend using a normal install of Go, not installing it in Msys2 with pacman. Go just needs gcc on the path.
From the terminal, running:
g++ --version
Should give something like:
g++ (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 8.1.0
I use the included makefile (requires make). If you prefer not to use make you can just look at the makefile to see what the build commands are. There is a make included with mingw_w64 but it's called mingw32_make.exe You can make a copy and rename it to make.exe
You should be able to run the tests with the usual: go test -short ./..
Or you can use make test
To run the portable tests (shared with cSuneido and jSuneido) you need to clone or download the separate Github repository. It needs to be a peer of the gsuneido directory, and must be called suneido_tests. e.g. c:/stuff/mygsuneido and c:/stuff/suneido_tests
All my development and testing has been on 64 bit. In theory you could build a 32 bit version of gSuneido but I suspect it would require some changes. It might be useful for client mode since it would use less memory because pointers and int's would be smaller (32 bits instead of 64) The client is unlikely to need access to more than 2gb of memory.
I try to fix warnings but depending on what checker you use, you may get some.
My normal environment is Visual Studio Code with the Go extension using gopls.