This package has a flaky test FTBFS blocking testing migration.

https://ci.debian.net/packages/g/golang-github-prometheus-exporter-toolkit/testing/armhf/74276304/#L1994

195s === RUN   TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_invalid_SAN_DNS_entries)
195s time=2026-08-11T16:34:42.505Z level=INFO msg="Listening on" address=[::]:33011
195s time=2026-08-11T16:34:42.508Z level=INFO msg="TLS is enabled." http2=true address=[::]:33011
195s 2026/08/11 16:34:42 http: TLS handshake error from [::1]:50182: could not find allowed SANs in client cert, found: [bad]
195s     tls_config_test.go:570: Expected error matching regular expression: bad certificate
195s     tls_config_test.go:571: Got: Get "https://localhost:33011": write tcp [::1]:50182->[::1]:33011: write: connection reset by peer
195s === RUN   TestServerBehaviour/valid_rate_limiter_(no_rate_limiter_set_up)_that_doesn't_block
...
195s     --- PASS: TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_good_SAN_DNS_entry) (0.39s)
195s     --- FAIL: TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_invalid_SAN_DNS_entries) (0.35s)
195s     --- PASS: TestServerBehaviour/valid_rate_limiter_(no_rate_limiter_set_up)_that_doesn't_block (0.25s)
...

/Simon

severity 1144163 important
thanks

This one still happens.  Bumping severity because it is a FTBFS
condition.

https://ci.debian.net/packages/g/golang-github-prometheus-exporter-toolkit/testing/armhf/76907789/#L1977

238s === RUN   TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_good_SAN_DNS_entry)
238s time=2026-10-20T09:33:17.777Z level=INFO msg="Listening on" address=[::]:33597
238s time=2026-10-20T09:33:17.780Z level=INFO msg="TLS is enabled." http2=true address=[::]:33597
238s === RUN   TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_invalid_SAN_DNS_entries)
238s time=2026-10-20T09:33:18.127Z level=INFO msg="Listening on" address=[::]:33597
238s time=2026-10-20T09:33:18.130Z level=INFO msg="TLS is enabled." http2=true address=[::]:33597
238s 2026/10/20 09:33:18 http: TLS handshake error from [::1]:49364: could not find allowed SANs in client cert, found: [bad]
238s     tls_config_test.go:570: Expected error matching regular expression: bad certificate
238s     tls_config_test.go:571: Got: Get "https://localhost:33597": write tcp [::1]:49364->[::1]:33597: write: connection reset by peer
238s === RUN   TestServerBehaviour/valid_rate_limiter_(no_rate_limiter_set_up)_that_doesn't_block
238s time=2026-10-20T09:33:18.482Z level=INFO msg="Listening on" address=[::]:33597
238s time=2026-10-20T09:33:18.482Z level=INFO msg="TLS is disabled." http2=false address=[::]:33597
238s === RUN   TestServerBehaviour/valid_rate_limiter_with_an_interval_of_one_second
238s time=2026-10-20T09:33:18.737Z level=INFO msg="Listening on" address=[::]:33597
238s time=2026-10-20T09:33:18.737Z level=INFO msg="Rate Limiter is enabled." burst=0 interval=1s
238s time=2026-10-20T09:33:18.737Z level=INFO msg="TLS is disabled." http2=false address=[::]:33597
238s --- FAIL: TestServerBehaviour (7.44s)
...
238s     --- FAIL: TestServerBehaviour/valid_tls_config_yml_and_tls_client_with_VerifyPeerCertificate_(present_invalid_SAN_DNS_entries) (0.35s)

/Simon