Go "cannot load X: malformed module path" - Fix in CI

By Daniel Zoghalchali·Latchkey

Module paths follow strict rules - a host, valid path elements, no leading dots, no uppercase escapes out of place. A path that breaks those rules is rejected as malformed before any download.

What this error means

A build fails with cannot load X: malformed module path "X": <reason>. Common reasons are a missing dot in the first element, an invalid character, or a trailing slash. It usually traces to a typo in go.mod or an import.

go: cannot load github.com//foo/bar: malformed module path "github.com//foo/bar": invalid path element ""

Common causes

Typo in the module or import path

A double slash, trailing slash, or invalid character makes the path fail validation.

Missing dot in the first element

A non-stdlib path whose first element has no dot is not a valid module path.

How to fix it

Correct the path syntax

1. Fix the malformed path in go.mod or the offending import to a valid module path.
2. Run go mod tidy to re-resolve.

go mod tidy
go build ./...

Verify against the real module path

1. Confirm the path matches the module declaration on its host, character for character.

go list -m github.com/foo/bar

How to prevent it

• Copy module paths exactly from the upstream go.mod.
• Avoid double or trailing slashes in import paths.
• Run go mod tidy after editing go.mod by hand.

Frequently asked questions

Related guides

References

• Go documentation
• GitHub Actions documentation