PackedBinary contains some logic separating two cases: whether only files are extracted from a tar, or whether folders are extracted.
if os.path.isdir(srcpath): # copy files to install dir via Binary self.cfg['start_dir'] = src Binary.install_step(self) elif os.path.isfile(srcpath): shutil.copy2(srcpath, self.installdir)
When folders are extracted (i.e. the 'if' is true), Binary.install_step is called, which executes install_cmd. However, when only files are extracted (the 'elif' scenario), it only copies the files, and the install_cmd is not executed.
For this scenario, PackedBinary should either execute the install_cmd, or return an error (or at least a warning in the log) that the install_cmd is being ignored.