...mainly due to arbitrarily failing ci builds, as this doesn't appear
to affect local builds/nix builds on remote builders, just fresh builds
in the ci.
the explanation for why this is happening might be that certain package
VCS's don't allow many/frequent connections from IP ranges other than
GOPROXY's (Google's).
that is sheer speculation, though.
however, it is still true that there are "no" failed ci builds with
GOPROXY env var set to its default value (left untouched), which does
indeed indicate that the above mentioned might be the root cause of the
issue after all.
this commit reverts:
* f3e481395e
and partially reverts:
* 14ba7b18bf
GOPROXY=direct has been kept for `nix-shell`/`nix develop` environments
as that is not where it poses an issue.
...such as flake files or {shell,default}.nix to reduce the necessity to
rebuild (when using `nix build`) after each change, even to non-go
files. more files can be added to an exclude list in the future.
* add 'version' command - "go-xkcdreader version" returns a formatted
version of the app
* test (among other things) that the version in flake.nix matches the
version hardcoded in app's go code (cmd/version.go)
* reformat the flake
* create a fyne application, specify deps as both buildGoModule
buildInputs and packages in devShells
* add nixGL overlay to devShells so that openGL-based apps (such as fyne
apps) run fine for non-NixOS users
* add build/link flags
