Errors for merge request created after upgrading to 15.2.2

Summary

After upgrading to Gitlab EE 15.2.2, there's errors when accessing to new merge request (no errors for MR created before the upgrade) Happens on a several projects/orgs

Steps to reproduce

• Create a MR
• Go on the MR

What is the current bug behavior?

MR created after the upgrade

What is the expected correct behavior?

MR created before the upgrade

Relevant logs and/or screenshots

Here's some logs:

gitaly:

{"correlation_id":"9e0a343b95ec7f3d1de17fdd3833b8ba","error":"merge: starting process [/var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15 -log-format json -log-level  -correlation-id 9e0a343b95ec7f3d1de17fdd3833b8ba -enabled-feature-flags  -disabled-feature-flags  merge]: fork/exec /var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15: permission denied","grpc.meta.auth_version":"v2","grpc.meta.client_name":"gitlab-sidekiq","grpc.meta.deadline_type":"unknown","grpc.meta.method_type":"unary","grpc.method":"UserMergeToRef","grpc.request.deadline":"2022-08-03T18:24:16.047","grpc.request.fullMethod":"/gitaly.OperationService/UserMergeToRef","grpc.request.glProjectPath":"xxx/xxxxx","grpc.request.glRepository":"project-92","grpc.request.repoPath":"@hashed/82/41/8241649609f88ccd2a0a5b233a07a538ec313ff6adf695aa44a969dbca39f67d.git","grpc.request.repoStorage":"default","grpc.service":"gitaly.OperationService","grpc.start_time":"2022-08-03T12:24:16.047","level":"error","msg":"unable to create merge commit","peer.address":"@","pid":15764,"remote_ip":"62.240.254.34","source_sha":"4b16a326bf80a1e34e4a2781490b253761fc98fb","span.kind":"server","system":"grpc","target_ref":"refs/merge-requests/273/merge","target_sha":"961d7973cf8459aacef4df2a4733e62444067787","time":"2022-08-03T10:24:16.056Z","username":"florian.tremblot"}

gitlab-rails:

GRPC::Internal (13:conflicts: starting process [/var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15 -log-format json -log-level  -correlation-id 01G9HMCSZPVSFHQNNEMX5EVTYC -enabled-feature-flags  -disabled-feature-flags  conflicts]: fork/exec /var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15: permission denied. debug_error_string:{"created":"@1659522934.992304458","description":"Error received from peer unix:/var/opt/gitlab/gitaly/gitaly.socket","file":"src/core/lib/surface/call.cc","file_line":1063,"grpc_message":"conflicts: starting process [/var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15 -log-format json -log-level  -correlation-id 01G9HMCSZPVSFHQNNEMX5EVTYC -enabled-feature-flags  -disabled-feature-flags  conflicts]: fork/exec /var/opt/gitlab/gitaly/run/gitaly-15764/gitaly-git2go-v15: permission denied","grpc_status":13}):
  config/initializers/enumerator_next_patch.rb:9:in `block (2 levels) in '
  lib/gitlab/gitaly_client/call.rb:43:in `block (3 levels) in instrument_stream'
  lib/gitlab/gitaly_client/call.rb:55:in `recording_request'
  lib/gitlab/gitaly_client/call.rb:43:in `block (2 levels) in instrument_stream'
  lib/gitlab/gitaly_client/call.rb:42:in `loop'
  lib/gitlab/gitaly_client/call.rb:42:in `block in instrument_stream'
  lib/gitlab/gitaly_client/conflict_files_stitcher.rb:18:in `each'
  lib/gitlab/gitaly_client/conflict_files_stitcher.rb:18:in `each'
  lib/gitlab/gitaly_client/conflict_files_stitcher.rb:18:in `each'
  lib/gitlab/gitaly_client/conflicts_service.rb:29:in `any?'
  lib/gitlab/gitaly_client/conflicts_service.rb:29:in `conflicts?'
  lib/gitlab/git/repository.rb:994:in `can_be_merged?'
  app/models/merge_request.rb:1242:in `notify_conflict?'
  app/models/merge_request.rb:237:in `block (2 levels) in '
  lib/gitlab/database/load_balancing/connection_proxy.rb:120:in `block in write_using_load_balancer'
  lib/gitlab/database/load_balancing/load_balancer.rb:115:in `block in read_write'
  lib/gitlab/database/load_balancing/load_balancer.rb:184:in `retry_with_backoff'
  lib/gitlab/database/load_balancing/load_balancer.rb:111:in `read_write'
  lib/gitlab/database/load_balancing/connection_proxy.rb:119:in `write_using_load_balancer'
  lib/gitlab/database/load_balancing/connection_proxy.rb:71:in `transaction'
  lib/gitlab/database.rb:331:in `block in transaction'
  lib/gitlab/database.rb:330:in `transaction'
  app/models/concerns/cross_database_modification.rb:99:in `transaction'
  app/services/merge_requests/mergeability_check_service.rb:123:in `update_merge_status'
  app/services/merge_requests/mergeability_check_service.rb:60:in `check_mergeability'
  app/services/merge_requests/mergeability_check_service.rb:48:in `block in execute'
  lib/gitlab/exclusive_lease_helpers.rb:38:in `in_lock'
  app/services/merge_requests/mergeability_check_service.rb:86:in `in_write_lock'
  app/services/merge_requests/mergeability_check_service.rb:42:in `execute'
  app/models/merge_request.rb:1113:in `check_mergeability'
  app/models/merge_request.rb:1155:in `mergeable?'
  ee/app/models/ee/merge_request.rb:129:in `mergeable?'
  lib/gitlab/graphql/present/field_extension.rb:18:in `resolve'
  lib/gitlab/graphql/tracers/timer_tracer.rb:20:in `trace'
  lib/gitlab/graphql/tracers/logger_tracer.rb:14:in `trace'
  lib/gitlab/graphql/tracers/metrics_tracer.rb:13:in `trace'
  lib/gitlab/graphql/tracers/application_context_tracer.rb:23:in `trace'
  lib/gitlab/graphql/tracers/timer_tracer.rb:20:in `trace'
  lib/gitlab/graphql/generic_tracing.rb:48:in `with_labkit_tracing'
  lib/gitlab/graphql/generic_tracing.rb:38:in `platform_trace'
  lib/gitlab/graphql/tracers/logger_tracer.rb:14:in `trace'
  lib/gitlab/graphql/tracers/metrics_tracer.rb:13:in `trace'
  lib/gitlab/graphql/tracers/application_context_tracer.rb:23:in `trace'
  lib/gitlab/graphql/tracers/timer_tracer.rb:20:in `trace'
  lib/gitlab/graphql/generic_tracing.rb:48:in `with_labkit_tracing'
  lib/gitlab/graphql/generic_tracing.rb:38:in `platform_trace'
  lib/gitlab/graphql/tracers/logger_tracer.rb:14:in `trace'
  lib/gitlab/graphql/tracers/metrics_tracer.rb:13:in `trace'
  lib/gitlab/graphql/tracers/application_context_tracer.rb:23:in `trace'
  app/graphql/gitlab_schema.rb:51:in `multiplex'
  app/controllers/graphql_controller.rb:160:in `execute_multiplex'
  app/controllers/graphql_controller.rb:57:in `execute'
  ee/lib/gitlab/ip_address_state.rb:10:in `with'
  ee/app/controllers/ee/application_controller.rb:45:in `set_current_ip_address'
  app/controllers/application_controller.rb:531:in `set_current_admin'
  lib/gitlab/session.rb:11:in `with_session'
  app/controllers/application_controller.rb:522:in `set_session_storage'
  lib/gitlab/i18n.rb:107:in `with_locale'
  lib/gitlab/i18n.rb:113:in `with_user_locale'
  app/controllers/application_controller.rb:516:in `set_locale'
  app/controllers/application_controller.rb:510:in `set_current_context'
  lib/gitlab/middleware/memory_report.rb:13:in `call'
  lib/gitlab/middleware/speedscope.rb:13:in `call'
  lib/gitlab/database/load_balancing/rack_middleware.rb:23:in `call'
  lib/gitlab/jira/middleware.rb:19:in `call'
  lib/gitlab/middleware/go.rb:20:in `call'
  lib/gitlab/etag_caching/middleware.rb:21:in `call'
  lib/gitlab/middleware/query_analyzer.rb:11:in `block in call'
  lib/gitlab/database/query_analyzer.rb:37:in `within'
  lib/gitlab/middleware/query_analyzer.rb:11:in `call'
  lib/gitlab/middleware/multipart.rb:173:in `call'
  lib/gitlab/middleware/read_only/controller.rb:50:in `call'
  lib/gitlab/middleware/read_only.rb:18:in `call'
  lib/gitlab/middleware/same_site_cookies.rb:27:in `call'
  lib/gitlab/middleware/handle_malformed_strings.rb:21:in `call'
  lib/gitlab/middleware/basic_health_check.rb:25:in `call'
  lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in `call'
  lib/gitlab/middleware/request_context.rb:21:in `call'
  lib/gitlab/middleware/webhook_recursion_detection.rb:15:in `call'
  config/initializers/fix_local_cache_middleware.rb:11:in `call'
  lib/gitlab/middleware/compressed_json.rb:26:in `call'
  lib/gitlab/middleware/rack_multipart_tempfile_factory.rb:19:in `call'
  lib/gitlab/middleware/sidekiq_web_static.rb:20:in `call'
  lib/gitlab/metrics/requests_rack_middleware.rb:77:in `call'
  lib/gitlab/middleware/release_env.rb:13:in `call'

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:         Debian 10
Proxy:          HTTPS_PROXY: http://xxxx:3128
                no_proxy: 0,127.0.0.1,localhost,gitlab,gitlab-01
                NO_PROXY: 0,127.0.0.1,localhost,gitlab,gitlab-01
                https_proxy: http://xxxx:3128
                http_proxy: http://xxxx:3128
                ftp_proxy: http://xxxx:3128
                FTP_PROXY: http://xxxx:3128
                HTTP_PROXY: http://xxxx:3128
Current User:   git
Using RVM:      no
Ruby Version:   2.7.5p203
Gem Version:    3.1.4
Bundler Version:2.3.15
Rake Version:   13.0.6
Redis Version:  6.2.7
Sidekiq Version:6.4.0
Go Version:     unknown

GitLab information
Version:        15.2.2-ee
Revision:       4420a6308aa
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     PostgreSQL
DB Version:     12.10
URL:            https://git.xxxxx.com
HTTP Clone URL: https://git.xxxxx.com/some-group/some-project.git
SSH Clone URL:  git@git.xxxxx.com:some-group/some-project.git
Elasticsearch:  no
Geo:            no
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers:

GitLab Shell
Version:        14.9.0
Repository storage paths:
- default:      /var/opt/gitlab/git-data/repositories
GitLab Shell path:              /opt/gitlab/embedded/service/gitlab-shell

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 14.9.0 ? ... OK (14.9.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes (cluster/worker) ... 1/1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Systemd unit files or init script exist? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Systemd unit files or init script up-to-date? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Projects have namespace: ...
2/1 ... yes
8/2 ... yes
4/3 ... yes
2/4 ... yes
2/5 ... yes
2/6 ... yes
2/7 ... yes
4/8 ... yes
2/9 ... yes
2/10 ... yes
2/11 ... yes
2/12 ... yes
2/13 ... yes
20/14 ... yes
4/15 ... yes
29/16 ... yes
20/17 ... yes
2/18 ... yes
2/19 ... yes
37/20 ... yes
3/21 ... yes
3/22 ... yes
3/24 ... yes
3/25 ... yes
3/26 ... yes
3/27 ... yes
3/28 ... yes
46/30 ... yes
2/31 ... yes
3/32 ... yes
50/33 ... yes
29/34 ... yes
29/35 ... yes
29/37 ... yes
29/38 ... yes
42/40 ... yes
42/42 ... yes
42/43 ... yes
50/44 ... yes
74/45 ... yes
59/46 ... yes
74/47 ... yes
37/48 ... yes
50/49 ... yes
60/50 ... yes
60/51 ... yes
59/52 ... yes
50/53 ... yes
2/54 ... yes
50/55 ... yes
74/56 ... yes
74/57 ... yes
74/60 ... yes
3/61 ... yes
3/62 ... yes
74/63 ... yes
74/64 ... yes
90/65 ... yes
2/66 ... yes
3/67 ... yes
52/68 ... yes
29/69 ... yes
2/70 ... yes
95/71 ... yes
4/73 ... yes
74/75 ... yes
50/76 ... yes
95/77 ... yes
59/78 ... yes
59/79 ... yes
2/80 ... yes
2/81 ... yes
2/82 ... yes
2/83 ... yes
59/84 ... yes
50/85 ... yes
50/87 ... yes
20/88 ... yes
2/89 ... yes
52/90 ... yes
50/91 ... yes
2/92 ... yes
95/94 ... yes
50/95 ... yes
50/96 ... yes
2/97 ... yes
2/98 ... yes
2/99 ... yes
4/100 ... yes
Redis version >= 6.0.0? ... yes
Ruby version >= 2.7.2 ? ... yes (2.7.5)
Git user has default SSH configuration? ... yes
Active users: ... 92
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes
Elasticsearch version 7.x-8.x or OpenSearch version 1.x ... skipped (Advanced Search is disabled)
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished