log4j2: coverage builds are failing

[vy]

log4j2¹ coverage builds have been failing for quite a while, the last successful coverage build was on 2023-10-06. The coverage failures in the last couple of months have been in the following form:

Starting Step #5
Step #5: Already have image (with digest): gcr.io/oss-fuzz-base/base-runner
Step #5: warning [/corpus/log4j-core-fuzz-test-PatternLayoutFuzzer.zip]:  zipfile is empty
Step #5: Failed to unpack the corpus for log4j-core-fuzz-test-PatternLayoutFuzzer. 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.
...
Step #5: ********************************************************************************
Step #5: Code coverage report generation failed.
Step #5: To reproduce, run:
Step #5: python infra/helper.py build_image log4j2
Step #5: python infra/helper.py build_fuzzers --sanitizer coverage log4j2
Step #5: python infra/helper.py coverage log4j2
Step #5: ********************************************************************************
Finished Step #5

I am able to locally trigger a coverage failure, but a slightly different one?

$ python infra/helper.py coverage $PROJECT_NAME
INFO:__main__:Downloading corpora for log4j2 project to /home/vy/Projects/google-oss-fuzz~master/build/corpus/log4j2.
warning [/home/vy/Projects/google-oss-fuzz~master/build/corpus/log4j2/log4j-layout-template-json-fuzz-test-JsonTemplateLayoutFuzzer.zip]:  zipfile is empty
ERROR:__main__:Corpus download for log4j-layout-template-json-fuzz-test-JsonTemplateLayoutFuzzer failed: Command '['unzip', '-q', '-o', '/home/vy/Projects/google-oss-fuzz~master/build/corpus/log4j2/log4j-layout-template-json-fuzz-test-JsonTemplateLayoutFuzzer.zip', '-d', '/home/vy/Projects/google-oss-fuzz~master/build/corpus/log4j2/log4j-layout-template-json-fuzz-test-JsonTemplateLayoutFuzzer']' returned non-zero exit status 1..
...

I guess log4j2 corpus is for some reason not getting stored. An infrastructural issue? In #12417, @jonathanmetzman pointed me to google/clusterfuzz#4238. Maybe related?

¹ log4j2 fuzzers were recently revamped in #12304.