oss-fuzz: The `code coverage` for the `libzip` project is failing.

Hello!

I’m working on expanding the fuzzing coverage of the libzip project. I have added new fuzzers as well as new corpora. The last two builds were successful except for generating a coverage report and the introspector.

I have observed the following problem: https://oss-fuzz-build-logs.storage.googleapis.com/log-d3820902-fdef-4ba9-b718-a635b711d339.txt https://oss-fuzz-build-logs.storage.googleapis.com/log-544ef7f0-d387-4f43-a38b-c2cca0921011.txt

Step #5: Already have image (with digest): gcr.io/oss-fuzz-base/base-runner
Step #5: [/corpus/zip_read_file_fuzzer.zip]
Step #5:   End-of-central-directory signature not found.  Either this file is not
Step #5:   a zipfile, or it constitutes one disk of a multi-part archive.  In the
Step #5:   latter case the central directory and zipfile comment will be found on
Step #5:   the last disk(s) of this archive.
Step #5: unzip:  cannot find zipfile directory in one of /corpus/zip_read_file_fuzzer.zip or
Step #5:         /corpus/zip_read_file_fuzzer.zip.zip, and cannot find /corpus/zip_read_file_fuzzer.zip.ZIP, period.
Step #5: Failed to unpack the corpus for zip_read_file_fuzzer. This usually means that corpus backup for a particular fuzz target does not exist. If a fuzz target was added in the last 24 hours, please wait one more day. Otherwise, something is wrong with the fuzz target or the infrastructure, and corpus pruning task does not finish successfully.

I have waited for more than 24 hours, even more than 48 hours. I have also checked coverage locally as well as the introspector, and it worked well. I got 80% coverage (delta = 24%) for all the added fuzzers. Can you please specify what’s going wrong with the corpus backup ? I would like to fix this issue.

Thank you!