Verified answers to concrete engineering failures.
Every entry states the error, the root cause, the fix, the versions it applies to, and the primary sources that prove it. Each one carries the date it was last checked against those sources, and says plainly when it does not apply.
Written to be read fast — by an engineer with a broken system, or by an agent with a token budget. Every page is also available as JSON, Markdown, and plain text.
## Index7 knowledge objects
Container terminated with exit code 137 and reason OOMKilled
highExit code 137 means the process received SIGKILL (128 + 9). In Kubernetes it almost always means the container breached its own memory limit and the cgroup OOM killer ended it — a different failure from the node running out of memory, which evicts the pod instead.
/k/container-exit-code-137-oomkilled · kubernetes · 4 sources · verified 2026-08-07 · 137 OOMKilled SIGKILL
Kubernetes pod fails with CreateContainerConfigError
highThe image pulled fine, but the kubelet cannot assemble the container's configuration: a referenced ConfigMap or Secret does not exist, or exists without the key the pod asks for. The pod stays in Waiting and no container is ever created.
/k/kubernetes-createcontainerconfigerror · kubernetes · 3 sources · verified 2026-08-07 · CreateContainerConfigError
Kubernetes pod stuck in CrashLoopBackOff
highCrashLoopBackOff is not an error in itself — it is the kubelet waiting between restarts of a container that keeps exiting. The exit code and reason on the previous container instance identify the actual failure; the backoff only controls how long you wait to see it again.
/k/kubernetes-crashloopbackoff · kubernetes · 4 sources · verified 2026-08-07 · CrashLoopBackOff BackOff
Kubernetes pod stuck in ImagePullBackOff or ErrImagePull
highThe kubelet cannot pull the image, so the container never starts. ErrImagePull is the first failure and ImagePullBackOff is the wait between retries — neither says why. The registry's own error text, printed in the pod's Events, is what identifies the cause.
/k/kubernetes-imagepullbackoff · kubernetes · 4 sources · verified 2026-08-07 · ImagePullBackOff ErrImagePull
Npgsql PostgresException 22001: value too long for type character varying(n)
highPostgreSQL rejects the write because a string exceeds the column's declared length. The error names the type and the limit but not the column, so the practical work is identifying which parameter overflowed — and PostgreSQL counts characters, not bytes.
/k/npgsql-22001-string-data-right-truncation · database · 4 sources · verified 2026-08-07 · 22001 string_data_right_truncation
React hydration failed: server HTML did not match the client
highHydration compares the server-rendered HTML against the first client render and fails when they differ. The cause is almost always one of three things: HTML the browser silently restructured, rendering logic that branches on the environment, or a value that changes between the two renders.
/k/nextjs-react-hydration-mismatch · framework · 4 sources · verified 2026-08-07 · 418 423 425
Stripe API returns 429 Too Many Requests
highStripe returns 429 for two unrelated reasons: you exceeded a rate or concurrency limit, or you hit an object lock timeout. The Stripe-Rate-Limited-Reason header tells you which, and only one of them is fixed by slowing down.
/k/stripe-429-rate-limit · api · 3 sources · verified 2026-08-07 · 429 lock_timeout
## For agentsstable, parseable renditions
Append an extension to any knowledge object URL to get it in a machine-readable form. The JSON body is versioned and carries the evidence list, the confidence rationale, and the freshness window as structured fields.
GET https://knowbase.sh/k/<slug>.json application/json
GET https://knowbase.sh/k/<slug>.md text/markdown
GET https://knowbase.sh/k/<slug>.txt text/plain
GET https://knowbase.sh/llms.txt index of every entryNo API key, no rate limit, CC-BY-4.0. Attribution is the canonical URL of the entry.