flaky tests(s) observed in `v26.2.0`

[debtquity]

Preflight checklist

• I could not find a solution in the existing issues, docs, nor discussions.
• I agree to follow this project's Code of Conduct.
• I have read and am following this repository's Contribution Guidelines.
• I have joined the Ory Community Slack.
• I am signed up to the Ory Security Patch Newsletter.

Ory Network Project

No response

Describe the bug

I am maintaining the oathkeeper package in NixOS/nixpkgs. I noticed the test suite was not running as part of CI and decided to add it as part of the build process, but I notice these tests appear to be flaky across builds and platforms:

Runs:

• [0] https://github.com/debtquity/nixpkgs-review-gha/actions/runs/23771423994
• [1] https://github.com/debtquity/nixpkgs-review-gha/actions/runs/23772807808
• [2] https://github.com/debtquity/nixpkgs-review-gha/actions/runs/23775808684

x86_64-linux

[1] TestAuthenticatorOAuth2Introspection/method=authenticate-with-cache/case=with_none_scope_strategy/case=second_request_does_use_cache_because_no_scope_was_requested_and_strategy_is_nil

x86_64-darwin

[0,1] TestAuthenticatorOAuth2Introspection/method=authenticate-with-cache/case=with_a_scope_scope_strategy/case=request_succeeds_and_uses_the_cache
[1,2] TestClientCredentialsCache/method=tokenToCache/case=cache_value
[1,2] TestClientCredentialsCache/method=tokenToCache/case=cached_invalid_json_value_should_not_working
[2] TestAuthenticatorOAuth2Introspection/method=authenticate-with-cache/case=with_none_scope_strategy/case=second_request_does_use_cache_because_no_scope_was_requested_and_strategy_is_nil

aarch64-darwin

[0,1,2] TestAuthenticatorOAuth2Introspection/method=authenticate-with-cache/case=with_none_scope_strategy/case=second_request_does_use_cache_because_no_scope_was_requested_and_strategy_is_nil
[0,1] TestAuthenticatorOAuth2Introspection/method=authenticate-with-cache/case=with_a_scope_scope_strategy/case=request_succeeds_and_uses_the_cache
[0] TestClientCredentialsCache/method=tokenToCache/case=cache_value
[0,2] TestClientCredentialsCache/method=tokenToCache/case=cached_invalid_json_value_should_not_working

Reproducing the bug

1. nixpkgs-review pr 502030

Relevant log output

oathkeeper> ERROR: Access credentials are invalid
oathkeeper>   Request: &{POST /oauth2/token HTTP/1.1 1 1 map[Accept-Encoding:[gzip] Authorization:[Basic Zm9vOmJhcg==] Content-Length:[29] Content-Type:[application/x-www-form-urlencoded] User-Agent:[Go-http-client/1.1]] 0x6e5877fce840 <nil> 29 [] false 127.0.0.1:49421 map[] map[] <nil> map[] 127.0.0.1:49422 /oauth2/token <nil> <nil> <nil>  0x6e5877ecd810 <nil> [] map[]}
oathkeeper>   Response Code: 401
oathkeeper>   Further Info: [An error occurred while handling a request]
oathkeeper> ERROR: The upstream service is not available
oathkeeper>   Request: &{POST /oauth2/token HTTP/1.1 1 1 map[Accept-Encoding:[gzip] Authorization:[Basic Y2xpZW50OnNlY3JldA==] Content-Length:[29] Content-Type:[application/x-www-form-urlencoded] User-Agent:[Go-http-client/1.1]] 0x6e5878db1680 <nil> 29 [] false 127.0.0.1:49466 map[] map[] <nil> map[] 127.0.0.1:49467 /oauth2/token <nil> <nil> <nil>  0x6e5878fe4280 <nil> [] map[]}
oathkeeper>   Response Code: 503
oathkeeper>   Further Info: [An error occurred while handling a request]
oathkeeper> ERROR: The upstream service is timing out
oathkeeper>   Request: &{POST /oauth2/token HTTP/1.1 1 1 map[Accept-Encoding:[gzip] Authorization:[Basic Y2xpZW50OnNlY3JldA==] Content-Length:[29] Content-Type:[application/x-www-form-urlencoded] User-Agent:[Go-http-client/1.1]] 0x6e5878279c40 <nil> 29 [] false 127.0.0.1:49468 map[] map[] <nil> map[] 127.0.0.1:49469 /oauth2/token <nil> <nil> <nil>  0x6e587817fbd0 <nil> [] map[]}
oathkeeper>   Response Code: 504
oathkeeper>   Further Info: [An error occurred while handling a request]
oathkeeper> ERROR: The upstream service encountered an unexpected error
oathkeeper>   Request: &{POST /oauth2/token HTTP/1.1 1 1 map[Accept-Encoding:[gzip] Authorization:[Basic Y2xpZW50OnNlY3JldA==] Content-Length:[29] Content-Type:[application/x-www-form-urlencoded] User-Agent:[Go-http-client/1.1]] 0x6e58791a2040 <nil> 29 [] false 127.0.0.1:49470 map[] map[] <nil> map[] 127.0.0.1:49471 /oauth2/token <nil> <nil> <nil>  0x6e5878fe4820 <nil> [] map[]}
oathkeeper>   Response Code: 500
oathkeeper>   Further Info: [An error occurred while handling a request]
oathkeeper> ERROR: Access credentials are not sufficient to access this resource
oathkeeper>   Request: &{POST /oauth2/token HTTP/1.1 1 1 map[Accept-Encoding:[gzip] Authorization:[Basic Y2xpZW50OnNlY3JldA==] Content-Length:[29] Content-Type:[application/x-www-form-urlencoded] User-Agent:[Go-http-client/1.1]] 0x6e58790c0980 <nil> 29 [] false 127.0.0.1:49474 map[] map[] <nil> map[] 127.0.0.1:49475 /oauth2/token <nil> <nil> <nil>  0x6e587922a410 <nil> [] map[]}
oathkeeper>   Response Code: 403
oathkeeper>   Further Info: [An error occurred while handling a request]

Relevant configuration

Version

v26.2.0

On which operating system are you observing this issue?

Other

In which environment are you deploying?

Binary

Additional Context

NixOS/nixpkgs#502030