theonedev/onedev · error · ValidationException

Pull request merge preview not calculated yet

Error message

Pull request merge preview not calculated yet

What it means

When running a job on a pull request, runBuild calls request.checkMergePreview(). If the merge preview has not been computed yet by the background merge-preview calculation, it returns null and the endpoint throws a ValidationException (HTTP 400). OneDev cannot determine which merge commit to build against.

Source

Thrown at server-core/src/main/java/io/onedev/server/rest/resource/JobRunResource.java:100

			commitId = ObjectId.fromString(jobRunOnCommit.getCommitHash());
			
			if (!gitService.isMergedInto(project, null, commitId, refCommit)) 
				throw new ValidationException("Specified commit is not reachable from specified ref");
			
			refName = jobRunOnCommit.getRefName();
			request = null;
		} else {
			JobRunOnPullRequest jobRunOnPullRequest = (JobRunOnPullRequest) jobRun;
			request = pullRequestService.load(jobRunOnPullRequest.getPullRequestId());
			refName = request.getMergeRef();
			project = request.getProject();
			
			if (!SecurityUtils.canRunJob(subject, request.getProject(), jobRun.getJobName()))		
				throw new UnauthorizedException();

			MergePreview preview = request.checkMergePreview();
			if (preview == null)
				throw new ValidationException("Pull request merge preview not calculated yet");
			if (preview.getMergeCommitHash() == null)
				throw new ValidationException("Pull request has merge conflicts");
			
			commitId = ObjectId.fromString(preview.getMergeCommitHash());
		}
		
		Build build = jobService.submit(user, project, commitId, jobRun.getJobName(), 
				jobRun.getParams(), refName, request, null, jobRun.getReason());
		if (build.isFinished())
			jobService.resubmit(user, build, jobRun.getReason());
		return build.getId();
    }

	@Api(order=200)
    @Path("/rebuild")
    @POST
    public Response rebuild(@NotNull @Valid JobRerun jobRerun) {
    	Build  build = buildService.load(jobRerun.buildId);

View on GitHub (pinned to d44925c47c)

Solutions

1. Wait/retry until the pull request shows a calculated merge preview in the UI, then resubmit
2. Trigger a merge preview recalculation (open/refresh the PR) and retry after a short delay
3. Add retry-with-backoff around the API call in automation scripts

Example fix

// before
runJobOnPullRequest(prId); // throws if preview not ready
// after
await pollUntilPrMergePreviewReady(prId, timeout=60s);
runJobOnPullRequest(prId);

// poll PR merge preview before submitting
while (getPullRequest(id).mergePreview == null && elapsed < timeout) sleep(backoff);

try { runBuild(pr); } catch (WebApplicationException e) { if (msg contains 'not calculated yet') retryWithBackoff(); else throw e; }

When it happens

Trigger: Submitting a job run on a pull request immediately after the PR was created or freshly updated, before OneDev finished calculating the merge preview.

Common situations: API automation racing PR creation; server under load delaying merge preview calculation; calling right after a push that invalidated the previous preview.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

• Pull request is closed
• Pull request has merge conflicts
• Reviewer needs to have read code permission to the project
• Assignee needs to have write code permission to the project
• This pull request is not eligible for auto-merge, as it can

AI-assisted analysis of theonedev/onedev@d44925c47c (2026-09-06). Data as JSON: /api/errors/af0cf644ea346a50. Report an issue: GitHub.