build: specify input fd to buildah
It solves a tight loop with poll as stdin will be initialized to
/dev/null in buildah/imagebuildah/StageExecutor.Run.
@@ -352,6 +352,7 @@ func buildCmd(c *cliconfig.BuildValues) error {
ContextDirectory: contextDir,
DefaultMountsFilePath: c.GlobalFlags.DefaultMountsFile,
Err: stderr,
+ In: os.Stdin,
ForceRmIntermediateCtrs: c.ForceRm,
IIDFile: c.Iidfile,
Labels: c.Label,
