Gimme much slower on Windows

Take for example this build: https://travis-ci.org/mvdan/sh/builds/449592402

On linux, gimme 1.11.x takes 4s. On OSX, it takes 10s. On Windows, it takes almost two minutes.

Is this by design? This is making Go builds on Windows painfully slow. Would be great to cut off those two minutes, especially since starting up a Windows job is already quite slow when compared to Linux.