Show Context Around the First Error

A log contains a clear error line, but the useful cause may be several lines above or below it.

Command

grep -RInC 3 -m 1 'ERROR' artifacts logs

Before you run this

System impact: Read-only. Can create load on large logs, directories, filesystems, or process tables.

When not to use it: Do not stop at the first match if the job continued and later failed for another reason.

Expected output

A small context block around the first ERROR match.

System impact

Read-only, can be slow. Nothing changes. grep prints the first ERROR match with nearby lines.

Scope this to the smallest useful path or service on busy systems.

Recovery / rollback: no state is changed.

When to use it

Use after finding which logs contain error markers.

When not to use it

Do not stop at the first match if the job continued and later failed for another reason.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ cd /work/ci-artifacts && grep -RIn 'ERROR' artifacts logs

artifacts/build/webpack.log:4:ERROR Module not found: Cannot resolve ./missing-module
artifacts/build/app-build.log:4:ERROR in src/server.ts:42: missing export createServer
artifacts/coverage/coverage-summary.txt:5:ERROR coverage below minimum threshold: statements 78.4 < 80.0

$ cd /work/ci-artifacts && grep -RInC 3 -m 1 'ERROR' artifacts logs

artifacts/build/webpack.log-1-webpack 5.91.0 compiled with 1 error
artifacts/build/webpack.log-2-asset main.js 245 KiB
artifacts/build/webpack.log-3-asset vendor.js 812 KiB
artifacts/build/webpack.log:4:ERROR Module not found: Cannot resolve ./missing-module
--
artifacts/build/app-build.log-1-Starting build
artifacts/build/app-build.log-2-Resolving dependencies
artifacts/build/app-build.log-3-Compiling app
artifacts/build/app-build.log:4:ERROR in src/server.ts:42: missing export createServer
artifacts/build/app-build.log-5-Build failed with exit code 1
--
artifacts/coverage/coverage-summary.txt-2-Statements: 78.4%
artifacts/coverage/coverage-summary.txt-3-Branches: 71.2%
artifacts/coverage/coverage-summary.txt-4-Functions: 81.0%
artifacts/coverage/coverage-summary.txt:5:ERROR coverage below minimum threshold: statements 78.4 < 80.0

$ cd /work/ci-artifacts && sed -n '1,12p' artifacts/build/app-build.log

Starting build
Resolving dependencies
Compiling app
ERROR in src/server.ts:42: missing export createServer
Build failed with exit code 1

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