Docker

Docker Build "Failed to Solve With Frontend Dockerfile.v0"

"Failed to solve with frontend dockerfile.v0" is BuildKit's generic wrapper message for a build failure — the actual specific problem is always in the more detailed message that follows immediately after it, which points to a genuine syntax error, missing file, or invalid instruction in your Dockerfile.

The Problem

A build fails with this generic-sounding error as the outer wrapper, followed by a more specific detail:

failed to solve with frontend dockerfile.v0: failed to create LLB definition: 
dockerfile parse error line 12: unknown instruction: RUNN

Or variations pointing to different underlying issues, all sharing the same generic outer wrapper message.

Why It Happens

"dockerfile.v0" refers to BuildKit's frontend responsible for parsing and processing your Dockerfile — this generic message appears whenever that frontend encounters any problem preventing it from successfully building the intended image graph. The actual cause varies, and is always described in the text immediately following this generic prefix:

  • A genuine syntax error in the Dockerfile — a typo in an instruction keyword (like RUNN instead of RUN), a malformed multi-line command, or invalid instruction ordering
  • A reference to a build context file that doesn't exist at the specified path, similar to (and sometimes overlapping with) the separate "failed to compute cache key" error category
  • An invalid or unsupported base image reference in a FROM instruction, such as a typo in the image name or an entirely nonexistent tag
  • Using a Dockerfile feature or syntax that requires a specific, newer syntax= directive at the top of the file that wasn't included, if the feature being used depends on a BuildKit frontend version beyond the implicit default

The Fix

Always read past the generic "failed to solve" prefix to the specific message that follows — this is where the actual, actionable information lives:

docker build -t your-app . 2>&1 | tail -20

Piping through tail ensures you see the final, most specific part of the error output, which is where the concrete cause is typically reported, rather than getting lost scrolling through a long build log.

For a syntax error specifically (a typo in an instruction, malformed formatting), open the exact line number referenced in the error and check it character by character against correct Dockerfile syntax:

# Correct instructions Docker recognizes:
FROM, RUN, CMD, LABEL, EXPOSE, ENV, ADD, COPY, ENTRYPOINT, VOLUME,
USER, WORKDIR, ARG, ONBUILD, STOPSIGNAL, HEALTHCHECK, SHELL

A single mistyped instruction keyword produces exactly this class of error, and is often the simplest, most common cause once you actually read the specific line and message referenced.

For a missing build context file, confirm the file genuinely exists at the exact path referenced, relative to wherever the build context root actually is:

ls -la path/referenced/in/error

For an invalid base image reference, confirm the image name and tag actually exist by checking directly against the registry:

docker pull the-exact-image:tag-from-your-dockerfile

If this pull itself fails, the Dockerfile's FROM line references something that genuinely doesn't exist (a typo in the image name, or a tag that was never published, or has since been removed), and correcting the reference to a valid image resolves the build failure.

If the error relates to using a newer Dockerfile feature, confirm you've included the appropriate syntax directive as the very first line of the file, which some newer instructions or features require to enable the corresponding BuildKit frontend behavior:

# syntax=docker/dockerfile:1
FROM node:18
# ... rest of Dockerfile

Still Not Working?

If the specific error message that follows the generic prefix still isn't clear enough to act on directly, try building with the legacy (non-BuildKit) builder temporarily as a diagnostic step — it sometimes produces a more traditional, differently-worded error message for the same underlying issue, which can occasionally be easier to interpret than BuildKit's more terse output for certain categories of Dockerfile mistakes:

DOCKER_BUILDKIT=0 docker build -t your-app .

This isn't a long-term fix (BuildKit is the modern, recommended builder with better performance and caching), but as a one-time diagnostic comparison, seeing the same failure reported through a different builder's error formatting can sometimes clarify an otherwise ambiguous BuildKit error message.

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