tar: Cannot update compressed archives error

[HarithaRamesh]

Ever since this PR (https://github.com/megastep/makeself/pull/149), I've been unable to build my self-extractable archive, I'm running into this error:

About to compress 7079540 KB of data...
Adding files to archive named "./output/artifact.up"...
tar: Cannot update compressed archives
Try 'tar --help' or 'tar --usage' for more information.
ERROR: failed to create temporary archive: /tmp/mkself28978.tar

Here is how I'm building it:

XZ_OPT="-1 --threads=0" ./makeself/makeself.sh \
     --needroot \
     --complevel 1 \
     --tar-extra "--use-compress-program=xz" \
     --untar-extra "-J" "./output/release" \
     "./output/artifact.up" "Self-Extractable Package Title" \
     "./install.sh" # my personal install script

Has anyone else seen this behaviour before? I was unable to find a workaround.

[realtime-neil]

Yep, that's on me since I changed the fundamental tar operation from create to append. I can think of a couple fixes, including but not limited to the following:

• revert my change; i.e., change append back to create
• maintain the separation between archive creation and compression; introduce something like a --compress-extra option and use the given flags during the compression step
• refactor how makeself.sh handles the compression to allow for the use of custom compress and decompress programs.

Alternatively, we could punt and say that flags related to compression are simply unsupported when given as --tar-extra.

[realtime-neil]

Possibly related: I've had my eye on the failing appendtest for a few weeks, now, and I think they way to solve it is to double-down on tar append. That is, we adopt the convention that all makeself operations proceed via the tar append operation and --- pointedly --- a fresh creation is a special case thereof since it appends to an empty precursor.

Refactoring as such would require that, in the case of a non-empty precursor, we implicitly decompress before attempting to append.

[realtime-neil]

@HarithaRamesh I should probably mention the workaround you want is to lose the --tar-extra and --untar-extra options (and arguments thereto); add the --xz option.

Moreover, the --complevel 1 option obviates the XZ_OPT=-1 variable assignment; I recommend keeping the former and losing the latter.

[HarithaRamesh]

@realtime-neil thank you for the response. I've tried the workaround and was able to get it working again. :)

Was there a decision made on fixing this? Or are you leaving flags related to compression when given as --tar-extra as unsupported?

EDIT: just for clarity, this is my new usage of makeself that worked

./makeself/makeself.sh \
     --needroot \
     --complevel 1 \
     --xz \
     "./output/release" \
     "./output/artifact.up" "Self-Extractable Package Title" \
     "./install.sh" # my personal install script

[realtime-neil]

@HarithaRamesh, I can't speak to others' intentions, but the very presence of the --gzip, --bzip2, --xz, etc options on makeself.sh gives me the impression that makeself.sh wants to take complete responsibility for compression/decompression. Speaking completely for myself, I prefer this subsumption of responsibilities because it allows makeself.sh to handle error conditions (e.g., missing decompression programs) that I would be forced to handle myself otherwise.

@megastep could you clarify where you want makeself.sh responsibilities to begin (and end) with regard to user-supplied tar flags?

[realtime-neil]

EDIT: just for clarity, this is my new usage of makeself that worked

./makeself/makeself.sh \
     --needroot \
     --complevel 1 \
     --xz \
     "./output/release" \
     "./output/artifact.up" "Self-Extractable Package Title" \
     "./install.sh" # my personal install script

Thank you for amending your post with the complete workaround in shell. IMHO, working example code is always in short supply and always welcome.