WithOsEnv assumes wrongly that os.Environ() returns only strings containing an equal sign

[apostasie]

https://github.com/compose-spec/compose-go/blob/main/cli/options.go#L240

This will call GetAsEqualsMap which will throw with an index out of bound in case a string does not contain an equal sign.

(we did hit that with a broken test in nerdctl - https://github.com/containerd/nerdctl/pull/3111)

[ndeloof]

In which circumstances does os.Envrion not return an equals sign? That's not clearly described by https://pkg.go.dev/os#Environ

[apostasie]

Thanks for fixing this @ndeloof

FWIW, a quick repro here: https://go.dev/play/p/JQw_6OA2--s

[ndeloof]

sure, but I wonder in which real circumstances os.Environ() would return a string without = sign.

[apostasie]

sure, but I wonder in which real circumstances os.Environ() would return a string without = sign.

I see your point. Agreed that it "should not happen under real/normal circumstances" (tm) :-).