Currently when using an mcopy -i to copy files from and hddimg is giving error due sanity check is not passed, we don't need those checks hence should be skipped. "Add mtools_skip_check=1 to your .mtoolsrc file to skip this test"
We likely need to "bitbake mtools-native" before executing this since we already have a patch for mtools which avoids this issue.
This is not a bug a correct implementation is tracked on bug 9903