Consider using `runtime/debug.BuildInfo` if build info not build with make.sh

[dtscd]

With go now embedding build versions into the binary, this could be used if built from: go install github.com/rfjakob/gocryptfs/v2@latest

Here is an example dump of what is present in each build:

/home/d/bin/gocryptfs: go1.19
	path	github.com/rfjakob/gocryptfs/v2
	mod	github.com/rfjakob/gocryptfs/v2	v2.2.1	h1:TzjjmN4tnRWffddDpG846lhMo63d4JQcWL8uZqnX1T0=
	dep	github.com/hanwen/go-fuse/v2	v2.1.1-0.20210825171523-3ab5d95a30ae	h1:4CB6T4YTUVvnro5ba8ju1QCbOuyGAeF3vvKlo50EJ4k=
	dep	github.com/jacobsa/crypto	v0.0.0-20190317225127-9f44e2d11115	h1:YuDUUFNM21CAbyPOpOP8BicaTD/0klJEKt5p8yuw+uY=
	dep	github.com/rfjakob/eme	v1.1.2	h1:SxziR8msSOElPayZNFfQw4Tjx/Sbaeeh3eRvrHVMUs4=
	dep	github.com/sabhiram/go-gitignore	v0.0.0-20201211210132-54b8a0bf510f	h1:8P2MkG70G76gnZBOPGwmMIgwBb/rESQuwsJ7K8ds4NE=
	dep	github.com/spf13/pflag	v1.0.5	h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
	dep	golang.org/x/crypto	v0.0.0-20210817164053-32db794688a5	h1:HWj/xjIHfjYU5nVXpTM0s39J9CbLn7Cc5a7IC5rwsMQ=
	dep	golang.org/x/sys	v0.0.0-20210817190340-bfb29a6856f2	h1:c8PlLMqBbOHoqtjteWm5/kbe6rNY2pbRfbIMVnepueo=
	dep	golang.org/x/term	v0.0.0-20210615171337-6886f2dfbf5b	h1:9zKuko04nR4gjZ4+DNjHqRlAJqbJETHwiNKDqTfOjfE=
	build	-compiler=gc
	build	CGO_ENABLED=1
	build	CGO_CFLAGS=
	build	CGO_CPPFLAGS=
	build	CGO_CXXFLAGS=
	build	CGO_LDFLAGS=
	build	GOARCH=amd64
	build	GOOS=linux
	build	GOAMD64=v1

This could be used where it currently print out:

gocryptfs [GitVersion not set - please compile using ./build.bash]; go-fuse [GitVersionFuse not set - please compile using ./build.bash]; 0000-00-00 go1.19 linux/amd64

The build date would not be present, but that isn't possible to have and have reproducible builds.

[rfjakob]

Good idea, looks like this added in Go 18: https://go.dev/doc/go1.18 . I currently support Go 1.13 and later, so this will likely have to wait a while

[dtscd]

Sure, if you want I could send a PR that conditional compiles for 1.18+ that will use the data if none otherwise available.

[rfjakob]

Yes, nice!

[dtscd]

@rfjakob PR #701 pushed. I discovered that the build information struct and function appears to be present from Go1.12. Your go.mod lists go1.16 and the CI goes back to Go1.13, so I didn't bother with a conditional build. It would still be easy to add if the CI finds a problem.