pkg-config not working from cgo in snap

[soumyaDghosh]

I have been trying to create a snap package for your gtkcord app, but it always complains about unable to find glib, gobject and other libraries. The pkg-config gives proper locations though.

snapcraft-gtkcord4-on-amd64-for-amd64-15306614 ../parts/gtkcord4/build# pkg-config --cflags --libs glib-2.0
-I/snap/gnome-42-2204-sdk/current/usr/include/glib-2.0 -I/snap/gnome-42-2204-sdk/current/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/snap/gnome-42-2204-sdk/current/usr/include -L/snap/gnome-42-2204-sdk/current/usr/lib/x86_64-linux-gnu -lglib-2.0

But, probably your code isn't looking there. Any way this can be helped? Thanks

[diamondburned]

What do you mean "probably"? What is the exact error? Does your go env contain anything weird?

[soumyaDghosh]

2023-12-16 21:01:22.242 Executing PosixPath('/root/parts/gtkcord4/run/build.sh')                                                                                            
2023-12-16 21:01:22.246 :: + go mod download all                                                                                                                            
2023-12-16 21:01:22.444 :: + go install -p 16 ./...                                                                                                                         
2023-12-16 21:01:24.368 :: go build github.com/diamondburned/gotk4/pkg/core/gextras:                                                                                        
2023-12-16 21:01:24.368 :: # pkg-config --cflags  -- glib-2.0                                                                                                               
2023-12-16 21:01:24.368 :: /snap/gnome-42-2204-sdk/current/usr/bin/pkg-config: error while loading shared libraries: libglib-2.0.so.0: cannot open shared object file: No such file or directory                                                                                                                                                         
2023-12-16 21:01:24.368 :: pkg-config: exit status 127                                                                                                                      
2023-12-16 21:01:24.368 :: go build github.com/diamondburned/gotk4/pkg/core/intern:                                                                                         
2023-12-16 21:01:24.368 :: # pkg-config --cflags  -- gobject-2.0                                                                                                            
2023-12-16 21:01:24.368 :: /snap/gnome-42-2204-sdk/current/usr/bin/pkg-config: error while loading shared libraries: libglib-2.0.so.0: cannot open shared object file: No such file or directory                                                                                                                                                         
2023-12-16 21:01:24.368 :: pkg-config: exit status 127                                                                                                                      
2023-12-16 21:01:24.368 :: go build github.com/diamondburned/gotk4/pkg/core/gbox:                                                                                           
2023-12-16 21:01:24.368 :: # pkg-config --cflags  -- glib-2.0                                                                                                               
2023-12-16 21:01:24.368 :: /snap/gnome-42-2204-sdk/current/usr/bin/pkg-config: error while loading shared libraries: libglib-2.0.so.0: cannot open shared object file: No such file or directory                                                                                                                                                         
2023-12-16 21:01:24.368 :: pkg-config: exit status 127                                                                                                                      
2023-12-16 21:01:24.417 Failed to run the build script for part 'gtkcord4'.                                                                                                 
2023-12-16 21:01:24.417 Launching shell on build environment...                                                                                                             
2023-12-16 21:01:24.417 Emitter: Pausing control of the terminal                                                                                                            
snapcraft-gtkcord4-on-amd64-for-amd64-15306614 ../project# 

This is the error that I am facing and this is go env as asked by you

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/root/.cache/go-build'
GOENV='/root/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/root/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/root/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/snap/go/10455'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/snap/go/10455/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.5'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build584678944=/tmp/go-build -gno-record-gcc-switches'
snapcraft-gtkcord4-on-amd64-for-amd64-15306614 ../project# 

The libraries are in the snap Gnome sdks folder. So, I need to add those flags here separately?

[diamondburned]

This might be an upstream problem. I'm not sure how Snap handles pkg-config with non-standard locations, but I didn't make cgo or pkg-config or snap, so I can't speak for any of them.

NixOS also does non-standard paths, and it uses $PKG_CONFIG_PATH_FOR_TARGET to create a list of pkg-config paths. This has always worked fine with that.

[diamondburned]

Also as a heads up, you ran this command:

pkg-config --cflags --libs glib-2.0

cgo wanted this command:

pkg-config --cflags  -- glib-2.0

What does running that exact command give you?

[soumyaDghosh]

snapcraft-gtkcord4-on-amd64-for-amd64-15306614 ../parts/gtkcord4/build# pkg-config --cflags  -- glib-2.0
-I/snap/gnome-42-2204-sdk/current/usr/include/glib-2.0 -I/snap/gnome-42-2204-sdk/current/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/snap/gnome-42-2204-sdk/current/usr/include

NixOS also does non-standard paths, and it uses $PKG_CONFIG_PATH_FOR_TARGET to create a list of pkg-config paths. This has always worked fine with that.

Here also we use the same, it's $PKG_CONFIG_PATH. This is the output of echo $PKG_CONFIG_PATH

/snap/gnome-42-2204-sdk/current/usr/lib/x86_64-linux-gnu/pkgconfig:/snap/gnome-42-2204-sdk/current/usr/lib/pkgconfig:/snap/gnome-42-2204-sdk/current/usr/share/pkgconfig

I am just not getting enough way to manually run those commands that are run by cgo itself. Also, there is nothing wrong with the sdk. I myself has published 50+ gnome apps, with this sdk. Things are often hardcoded, which make these issues.

[diamondburned]

Then this sounds more like a cgo issue. Again, I don't do anything to break pkg-config doing this, and it works perfectly fine on NixOS.

[soumyaDghosh]

Okay.. so, I created the snap using the prebuilt binary.