Error map

cgo: C compiler gcc not found Go: cgo: C compiler "gcc" not found: exec: "gcc": executable file not found in $PATH

Go · layer 4, Application & API

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Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.

cgo: C compiler gcc not found — Go: cgo: C compiler "gcc" not found: exec: "gcc": executable file not found in $PATH (Go)cgo: C comp…did not complete successfully — failed to solve: process "/bin/sh -c ..." did not complete successfully: exit code: 1 (Docker)did not complete su…lookup registry-1.docker.io: no such host — dial tcp: lookup registry-1.docker.io: no such host / Temporary failure in name resolution during docker build (Docker)lookup registry-1.d…failed to read dockerfile — failed to solve: failed to read dockerfile: open Dockerfile: no such file or directory (Docker)failed to read dock…unknown instruction — Dockerfile parse error line N: unknown instruction (Docker)unknown instructionCOPY failed — COPY failed: file not found in build context / "/app/x": not found (Docker)COPY failedmax depth exceeded — Error response from daemon: max depth exceeded (too many image layers) (Docker)max depth exceededforbidden path outside the build context — COPY failed: forbidden path outside the build context: ../file (Docker)forbidden path outs…exec format error — exec /usr/local/bin/docker-entrypoint.sh: exec format error (Docker)exec format errorSending build context — Docker build slow: "Sending build context to Docker daemon 2.5GB" / transferring context takes forever (Docker)Sending build conte…function main is undeclared in the main package — Go: runtime.main_main·f: function main is undeclared in the main package (Go)function main is un…cannot assign to struct field m[k].f in map — Go: cannot assign to struct field users["bob"].Age in map (Go)cannot assign to st…panic: assignment to entry in nil map — Go: panic: assignment to entry in nil map (Go)panic: assignment t…Unable to locate package — E: Unable to locate package (apt / apt-get install) (Linux)Unable to locate pa…Output directory not found — Cloudflare Pages build: Error: Output directory "dist" not found / Failed: build output directory not found (Cloudflare)Output directory no…NETSDK1045 — error NETSDK1045: The current .NET SDK does not support targeting .NET 8.0. Either target .NET 7.0 or lower, or use a version of the .NET SDK that supports .NET 8.0 (.NET)NETSDK1045ECONNREFUSED — Error: connect ECONNREFUSED 127.0.0.1:5432 (Node.js)ECONNREFUSED408 — HTTP 408 Request Timeout (HTTP)408Failed to fetch — TypeError: Failed to fetch / NetworkError when attempting to fetch resource (JavaScript)Failed to fetchMSB3027 — error MSB3027: Could not copy "obj\...\App.dll" to "bin\...\App.dll". Exceeded retry count of 10. The file is locked by: "App (1234)" (.NET)MSB3027undefined reference to — C/C++: undefined reference to `function' — collect2: error: ld returned 1 exit status (C/C++)undefined reference…no Go files in directory — Go: package app/cmd: no Go files in /app/cmd / build constraints exclude all Go files (Go)no Go files in dire…Parse error — PHP Parse error: syntax error, unexpected … (PHP)Parse errorIndentationError — IndentationError: unexpected indent / expected an indented block (Python)IndentationErrorELIFECYCLE — npm ERR! code ELIFECYCLE / Command failed with exit code 1 (npm)ELIFECYCLEnot a git repository — fatal: not a git repository (or any of the parent directories): .git (Git)not a git repositoryENOENT — Error: ENOENT: no such file or directory (Node.js)ENOENTcompose validation — docker compose: services.x Additional property y is not allowed / yaml: line N: mapping values are not allowed (Docker)compose validationENOSPC — no space left on device (Docker / Linux) (Docker)ENOSPCno matching manifest — no matching manifest for linux/arm64/v8 in the manifest list entries (Docker)no matching manifestconflict: unable to remove repository reference — conflict: unable to remove repository reference (must force) - container is using its referenced image (Docker)conflict: unable to…Cloud Functions: Build failed — Cloud Functions: Build failed: function.js does not exist / npm install failed with exit code 1 (Cloud Build step) (Google Cloud / Firebase)Cloud Functions: Bu…CrashLoopBackOff — Kubernetes: CrashLoopBackOff (Kubernetes)CrashLoopBackOffImagePullBackOff — Kubernetes: ImagePullBackOff / ErrImagePull (Kubernetes)ImagePullBackOffcommand not found — bash: command not found (Linux)command not found504 — HTTP 504 Gateway Timeout (HTTP)504524 — Cloudflare Error 524: A Timeout Occurred (Cloudflare)524304 — HTTP 304 Not Modified (HTTP)304imported and not used — Go: ./main.go:5:2: "os" imported and not used (Go)imported and not us…undefined: x — Go: ./main.go:12:2: undefined: handler (Go)undefined: xmissing return — Go: ./main.go:18:1: missing return (Go)missing returnno new variables on left side of := — Go: ./main.go:9:6: no new variables on left side of := (Go)no new variables on…invalid operation: mismatched types — Go: invalid operation: a + b (mismatched types int and float64) (Go)invalid operation: …cannot use x as type in assignment/argument — Go: cannot use "5" (untyped string constant) as int value in argument to f (Go)cannot use x as typ…invalid memory address or nil pointer dereference — Go: panic: runtime error: invalid memory address or nil pointer dereference (Go)invalid memory addr…panic: runtime error: index out of range — Go: panic: runtime error: index out of range [3] with length 3 (Go)panic: runtime erro…panic: slice bounds out of range — Go: panic: runtime error: slice bounds out of range [:5] with capacity 3 (Go)panic: slice bounds…

Directly related (12)

did not complete successfullyDocker

failed to solve: process "/bin/sh -c ..." did not complete successfully: exit code: 1

A RUN step in your Dockerfile failed. The real error is printed in the lines just above this message.

lookup registry-1.docker.io: no such hostDocker

dial tcp: lookup registry-1.docker.io: no such host / Temporary failure in name resolution during docker build

DNS isn’t working for the Docker daemon or inside build containers, so pulls and package downloads fail.

failed to read dockerfileDocker

failed to solve: failed to read dockerfile: open Dockerfile: no such file or directory

docker build can’t find a Dockerfile in the build context you passed.

unknown instructionDocker

Dockerfile parse error line N: unknown instruction

A line in the Dockerfile doesn’t start with a valid instruction — usually a broken line continuation or a typo.

COPY failedDocker

COPY failed: file not found in build context / "/app/x": not found

The Dockerfile COPY refers to a path outside the build context, excluded by .dockerignore, or relative to the wrong directory.

max depth exceededDocker

Error response from daemon: max depth exceeded (too many image layers)

The image has more layers than the storage driver allows (127 for overlay2), usually from repeatedly committing containers or ver…

forbidden path outside the build contextDocker

COPY failed: forbidden path outside the build context: ../file

A COPY/ADD tries to read a file above the build context (../something); Docker only sends the context folder to the builder.

exec format errorDocker

exec /usr/local/bin/docker-entrypoint.sh: exec format error

The container tried to run a binary built for a different CPU architecture (arm64 vs amd64) — or a script with a broken shebang /…

Sending build contextDocker

Docker build slow: "Sending build context to Docker daemon 2.5GB" / transferring context takes forever

docker build is uploading your whole project folder — node_modules, .git, data files — before building, because there’s no (or a…

function main is undeclared in the main packageGo

Go: runtime.main_main·f: function main is undeclared in the main package

The package is named `main` but contains no `func main()`, or you tried to build a library as an executable.

cannot assign to struct field m[k].f in mapGo

Go: cannot assign to struct field users["bob"].Age in map

Map values are not addressable, so you cannot modify a field of a struct stored directly in a map.

panic: assignment to entry in nil mapGo

Go: panic: assignment to entry in nil map

You wrote to a map that was declared but never initialised.

Two steps away (34)

Unable to locate packageLinux

E: Unable to locate package (apt / apt-get install)

apt can’t find the package name in its package lists — the lists are stale, the repository isn’t enabled, or the name is wrong fo…

Output directory not foundCloudflare

Cloudflare Pages build: Error: Output directory "dist" not found / Failed: build output directory not found

The Pages build finished, but the folder set as “Build output directory” doesn’t exist — the framework wrote its files somewhere…

NETSDK1045.NET

error NETSDK1045: The current .NET SDK does not support targeting .NET 8.0. Either target .NET 7.0 or lower, or use a version of the .NET SDK that supports .NET 8.0

The installed .NET SDK is older than the project’s TargetFramework.

ECONNREFUSEDNode.js

Error: connect ECONNREFUSED 127.0.0.1:5432

Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.

408HTTP

HTTP 408 Request Timeout

The server closed the connection because the client took too long to send the complete request.

Failed to fetchJavaScript

TypeError: Failed to fetch / NetworkError when attempting to fetch resource

The browser couldn’t complete the request at the network level — CORS, DNS, offline, blocked mixed content, or the server refused…

MSB3027.NET

error MSB3027: Could not copy "obj\...\App.dll" to "bin\...\App.dll". Exceeded retry count of 10. The file is locked by: "App (1234)"

The build can’t overwrite the output DLL/EXE because the app (or IIS Express, a test runner, antivirus) is still running and hold…

undefined reference toC/C++

C/C++: undefined reference to `function' — collect2: error: ld returned 1 exit status

The linker can’t find the definition of a function or variable that was declared and used.

no Go files in directoryGo

Go: package app/cmd: no Go files in /app/cmd / build constraints exclude all Go files

The directory you asked Go to build contains no buildable `.go` files.

Parse errorPHP

PHP Parse error: syntax error, unexpected …

PHP can’t parse the file because of a syntax mistake — the real error is often on the line before the one reported.

IndentationErrorPython

IndentationError: unexpected indent / expected an indented block

Python’s block structure is broken — inconsistent indentation or mixed tabs and spaces.

ELIFECYCLEnpm

npm ERR! code ELIFECYCLE / Command failed with exit code 1

An npm script (build, start, test, postinstall) exited with an error. ELIFECYCLE is only the wrapper — the real error is printed…

not a git repositoryGit

fatal: not a git repository (or any of the parent directories): .git

You ran a Git command outside a Git working tree.

ENOENTNode.js

Error: ENOENT: no such file or directory

A file or directory the program tried to open doesn’t exist at that path.

compose validationDocker

docker compose: services.x Additional property y is not allowed / yaml: line N: mapping values are not allowed

The compose file is invalid YAML or uses a key Compose doesn’t recognise at that level (usually an indentation mistake).

ENOSPCDocker

no space left on device (Docker / Linux)

The disk (or inode table) is full — Docker images, build cache, logs and volumes are common culprits.

no matching manifestDocker

no matching manifest for linux/arm64/v8 in the manifest list entries

The image has no build for your CPU architecture — typically pulling an amd64-only image on an Apple Silicon Mac or ARM server.

conflict: unable to remove repository referenceDocker

conflict: unable to remove repository reference (must force) - container is using its referenced image

You tried to delete an image that a container — even a stopped one — still uses.

Cloud Functions: Build failedGoogle Cloud / Firebase

Cloud Functions: Build failed: function.js does not exist / npm install failed with exit code 1 (Cloud Build step)

The deployment's build step (Cloud Build) failed, so no new function version was created.

CrashLoopBackOffKubernetes

Kubernetes: CrashLoopBackOff

The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.

ImagePullBackOffKubernetes

Kubernetes: ImagePullBackOff / ErrImagePull

The node can’t pull the container image — wrong name/tag, missing registry credentials, or registry unreachable.

command not foundLinux

bash: command not found

The shell can’t find an executable with that name in any directory on your PATH.

504HTTP

HTTP 504 Gateway Timeout

A proxy or gateway waited too long for the upstream server to respond and gave up.

524Cloudflare

Cloudflare Error 524: A Timeout Occurred

Cloudflare connected to the origin, but the origin didn’t send an HTTP response within 100 seconds.

304HTTP

HTTP 304 Not Modified

The cached copy is still valid, so the server sends no body and the client reuses its cache.

imported and not usedGo

Go: ./main.go:5:2: "os" imported and not used

The file imports a package that no code in that file uses; Go treats this as a compile error, not a warning.

undefined: xGo

Go: ./main.go:12:2: undefined: handler

The compiler cannot find an identifier — a typo, a missing import, or it lives in another file/package that wasn't built.

missing returnGo

Go: ./main.go:18:1: missing return

A function with a return type can reach its end without a return statement on some path.

no new variables on left side of :=Go

Go: ./main.go:9:6: no new variables on left side of :=

`:=` declares variables, but all names on the left already exist in the same scope.

invalid operation: mismatched typesGo

Go: invalid operation: a + b (mismatched types int and float64)

You combined two values of different types; Go never converts numeric types implicitly.

cannot use x as type in assignment/argumentGo

Go: cannot use "5" (untyped string constant) as int value in argument to f

A value's type is not assignable to the type required by the variable, parameter or return value.

invalid memory address or nil pointer dereferenceGo

Go: panic: runtime error: invalid memory address or nil pointer dereference

The program used a pointer, map, interface or struct field that was nil — usually an uninitialised value or an ignored error.

panic: runtime error: index out of rangeGo

Go: panic: runtime error: index out of range [3] with length 3

Code accessed a slice, array or string element beyond its length.

panic: slice bounds out of rangeGo

Go: panic: runtime error: slice bounds out of range [:5] with capacity 3

A slice expression `s[a:b]` used bounds outside the slice's length or capacity.