At some conditions Bamboo is unable to clear inconsistent git cache and perform change detection

2019-10-18 03:02:28,922 WARN [9-BAM::PlanExec:pool-16-thread-4] [AbstractGitExecutor] Deleting directory /var/vcap/store/atlassian-bamboo/xml-data/build-dir/_git-repositories-ca
che/18dcecf2d35a3ffacb7165829681b4f94640bd4a
2019-10-18 03:02:28,923 ERROR [9-BAM::PlanExec:pool-16-thread-4] [AbstractGitExecutor] Unable to delete files: [.git], expect trouble
2019-10-18 03:02:28,936 INFO [9-BAM::PlanExec:pool-16-thread-4] [DefaultChangeDetectionManager] Found 1672 open branches for xxxx-xxxx
2019-10-18 03:02:28,938 INFO [9-BAM::PlanExec:pool-16-thread-4] [DefaultErrorHandler] Recording an error: Unable to detect changes : xxxxx-xxxx : com.atlassian.bamboo.repository.RepositoryException: : Cannot fetch branch 'refs/heads/SBM-1290_Update__FOR_QA_MERGE_ONLY' from 'ssh://git@......com:7999/.../.....git' to source directory '/var/vcap/store/atlassian-bamboo/xml-data/build-dir/_git-repositories-cache/18dcecf2d35a3ffacb7165829681b4f94640bd4a'. command [/usr/bin/git fetch ssh://45dd5a04-ff0f-40e2-92d1-556630c29827@127.0.0.1:45257/..../......git +refs/heads/SBM-1290_Update__FOR_QA_MERGE_ONLY:refs/heads/SBM-1290_Update__FOR_QA_MERGE_ONLY --update-head-ok] failed with code 128. Working directory was [/var/vcap/store/atlassian-bamboo/xml-data/build-dir/_git-repositories-cache/18dcecf2d35a3ffacb7165829681b4f94640bd4a]., stderr:
fatal: Not a git repository (or any parent up to mount point /var/vcap)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).