Right now BGT ships for Linux only binaries for x86. The provided binaries are mosunpack, tis2bg2 and tisunpack.
mosunpack and tisunpack are part of WeiDU under Linux, but when running the amd64-version of WeiDU, BGT can't find a matching version of tis2bg2. So please ship a version of tis2bg2 compiled for amd64 too.
Also the mentioned binaries aren't executable inside of the BGT archives. Please make them executable too.