Known Issues and Solutions

Zip Central Directories

The zip file format stores a “table of contents” known as a central directory at the end of the file. This allows zip archives to be “random-access” in the sense that you don’t have to visit every file in the archive to know what files exist in the archive, but if a process is terminated forcefully (kill -9 or hitting a wall clock limit), libgetar will not get an opportunity to write the central directory. In this case, the zip file will be unreadable until you rebuild the central directory using the command line tool zip -FF or the python module gtar.fix (which uses zip -FF and deletes all data from any frames that were removed in the process). Example:

python -m gtar.fix -o

Some very large (>8GB) zip files seem to be unable to be fixed, even with zip -FF. In this case, to recover your data you can extract it all using the jar tool, which does not even look at the central directory when extracting:

mkdir temp && cd temp
jar xvf ../
zip -mr -xi ./*

Zip vs Zip64

The zip archives libgetar writes are always in the zip64 format. It can read “normal” zip archives just fine, but appending to them will not work since converting an archive in-place is unsafe in case of errors. Running the gtar.fix or gtar.copy.main() python modules will always convert a file to zip64 format. Example:

python -m gtar.copy

basic_string::_S_construct null not valid

This is due to passing in a python string object instead of a bytes object and is probably an error on my part. These errors look like this:

terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_S_construct null not valid

If you see any of those, let me know!

ImportError: cannot import name ‘_gtar’ from partially initialized module ‘gtar’

This typically stems from trying to import the gtar source directory directly as a python module. Since the python module depends on a compiled C extension, it must first be installed separately. To fix this, install the module (see Installation and Basic Usage) and run python outside of the libgetar source directory to avoid python automatically importing the gtar source directory.