compose: Add additional debuginfo

[HuijingHei]

When running compose image failed, get: error: compose tree failed: ExitStatus(unix_wait_status(256)), it is not easy to understand, this is to add some additional debuginfo when get error.

For example: error: compose tree failed: "error: bwrap test failed, see <https://github.com/coreos/rpm-ostree/pull/429>: Failed to execute child process “bwrap” (No such file or directory)\n"

[openshift-ci[bot]]

Skipping CI for Draft Pull Request. If you want CI signal for your change, please convert it to an actual PR. You can still manually trigger a test run with /test all