Compile cgo lib on Cygwin64: “ld: cannot find -lmi

Question

I'm trying to use a cgo library on Windows, namely github.com/mattn/go-sqlite3

I use Cygwin64 and installed with all "Development" packages, so gcc is availabe.

But running go get github.com/mattn/go-sqlite3 results in:

/usr/lib/gcc/x86_64-pc-cygwin/5.3.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lmingwex
/usr/lib/gcc/x86_64-pc-cygwin/5.3.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lmingw32

If I search for "mingwex" and "mingw32" in the Cygwin installer, I get no results. Am I looking for the wrong names or are they not available on 64 bit systems?

Or is there a better way to use the library on Windows?

---

Note that the README states that

However, if you install go-sqlite3 with go install github.com/mattn/go-sqlite3, you don't need gcc to build your app anymore

but I get the same error message if I use go install.

$ go version
go version go1.6.2 windows/amd64

Answer 1

I have encountered the same issue as well. It seems to me that cygwin is not fully compatible with cgo. Instead, I have used https://mingw-w64.org.

From the cgo documentation https://github.com/golang/go/wiki/cgo:

In order to use cgo on Windows, you'll also need to first install a gcc compiler (for instance, mingw-w64) and have gcc.exe (etc.) in your PATH environment variable before compiling with cgo will work.

Answer 2

What finally worked for me (instead of Cygwin) is to download TDM MinGW-w64 from http://tdm-gcc.tdragon.net/download and set the PATH such that gcc from C:\TDM-GCC-64\bin is used.

Answer 3

You can also install package mingw64-i686-gcc-core from Cygwin.

The binary will be /usr/bin/i686-w64-mingw32-gcc.exe so you probably need to copy it as /usr/bin/gcc.exe.