internal/rosa: set PYTHONUNBUFFERED=1

Some python tools try to be clever and buffers output. This makes the build process appear to hang and is quite frustrating. Instead of trying to address this on a case-by-case basis, this is turned off globally for the interpreter.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/rosa.go

@@ -199,6 +199,10 @@ func lastIndexFunc[S ~[]E, E any](s S, f func(E) bool) (i int) {
 
 // fixupEnviron fixes up PATH, prepends extras and returns the resulting slice.
 func fixupEnviron(env, extras []string, paths ...string) []string {
+	// some python tools try to be clever and buffers their output, making the
+	// build process appear to hang
+	env = append(env, "PYTHONUNBUFFERED=1")
+
 	const pathPrefix = "PATH="
 	pathVal := strings.Join(paths, ":")