Building with gccgo gives many import errors on large projects

$ gccgo --version
gccgo (Ubuntu 6.0.1-0ubuntu1) 6.0.0 20160414 (experimental) [trunk revision 234994]
$ go version
go version go1.8 linux/amd64
$ go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/NU-YP/code/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="/usr/bin/gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build894555238=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

I've tried to compile many large projects with gccgo, and it always fails even though gc succeeds.

As a representative example, let's look at github.com/derekparker/delve. I obtain the project and its dependencies with go get -u. I edit line 10 of the Makefile to read

BUILD_FLAGS=-ldflags="-X main.Build=$(BUILD_SHA)" -compiler gccgo

I run make install. I expect that gccgo will compile the program just as well as gc, but instead, it spits out hundreds of errors, so many that I'm not going to include them in this post; find them here instead. What am I doing wrong here?

I thought gccgo only supports up to go1.2...

From the Go 1.8 release notes:


Due to the alignment of Go's semiannual release schedule with GCC's annual release schedule, GCC release 6 contains the Go 1.6.1 version of gccgo. We expect that the next release, GCC 7, will contain the Go 1.8 version of gccgo.

I am using version 6 of gccgo, although my GCC version is:

gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609

You don't have gopkg.in/yaml.v2 in a place where gccgo can find it (or it was compiled with gc, which produces libraries that are incompatible with gccgo and must be recompiled with gccgo).
https://golang.org/doc/install/gccgo#Imports

What /u/MonkeeSage said.
The same supposedly applies to golang.org/x/debug/dwarf as well.