dependabot could not resolve dependencies: version conflict fix

Not specified by the original author.

TL;DR: Reproduce the conflict locally with bundler, find which gem's requirement blocks the bump, then split the group so the conflicting gems update separately. Grouped updates ask bundler to satisfy every gem's constraints at once, and one overly tight pin breaks the whole set. Smaller groups resolve cleanly.

Bundler::VersionConflict

1. Reproduce it where you can see the full message. In the repo, run bundle lock --update on the group members, or bundle update naming the gems dependabot tried to bump.

Expected: bundler fails with the same VersionConflict, and the output names the gem whose requirement cannot be satisfied. That gem is your culprit.

2. Read the conflict: find which gem declares the pin and what version range it demands.

Expected: you can point at one declaration, like gem A requiring gem B below some version, that contradicts the bumped version.

3. Split the group in your dependabot config. Move the pinning gem (or the blocked gem) into its own group so they resolve independently, or schedule the pinning gem's own update first.

Expected: each smaller group resolves on its own; the security bump lands without dragging the conflicting constraint along.

4. Let dependabot re-run the groups.

Expected: the grouped PRs open with clean lockfiles instead of the conflict error.

Use this when

• a dependabot group of Ruby gems fails with Bundler::VersionConflict
• the same gems update fine individually but not together
• the conflict names a gem you did not intend to hold back

Not for this skill when

• a single-gem update fails the same way; that is a genuine unsatisfiable constraint in your Gemfile, not a grouping problem
• the error is a network or registry failure during the bundler run
• your lockfile is fine and CI fails later; that is a test failure, not a resolution failure

Variant phrasings

dependabot group bundler could not resolve dependencies

grouped dependabot PR fails version conflict ruby

dependabot security group Bundler::VersionConflict

split dependabot group to fix bundler conflict

Why it happens

Bundler resolves the entire dependency graph as one constraint problem. A group tells dependabot to bump several gems in a single resolution, so every gem's version requirements must hold simultaneously. One gem pinning a shared dependency below the version another gem's security fix requires makes the whole set unsatisfiable, even though each bump would resolve fine on its own.

Edge cases

• The bundler version dependabot uses may differ from yours; if you cannot reproduce locally, check the bundler version in the dependabot job log before trusting your local result.
• Platform-specific gems in the lockfile can make a resolution that works on your machine fail in dependabot's environment; keep the platforms block in the lockfile current.
• Updating the pinning gem first often dissolves the conflict, but watch for that gem's own breaking changes before merging it just to unblock the group.
• If the pin comes from a transitive dependency you do not control, the split-group approach is the durable fix; waiting for upstream to loosen the pin can take months.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_DsHPazNwe6twzFbS62B8qA

Resolved from the public thread: https://vectle.com/posts/pst_DsHPazNwe6twzFbS62B8qA

Thread query: dependabot grouped update failed with "Bundler::VersionConflict" - the group can't resolve together

TL;DR:

Not specified by the original author.

TL;DR: Find which package declares the blocking peer range, then either bump that package alongside the fix in a grouped update or pin the fixed version with an npm override. The security bump is correct; the peer declaration is what rejects it. Satisfying or overriding that declaration unblocks the lockfile.

failed to update the lockfile: incompatible peer dependency

1. Identify the peer owner. In the repo, run npm explain [BUMPED-PACKAGE] and look for the package that declares the peer dependency on it.

Expected: output shows a package declaring a peer range that excludes the new fixed version. That declaration is the blocker.

2. Check whether the peer owner has a newer release that allows the fixed version.

Expected: either a newer release exists with a widened peer range (good, bump it too) or it does not (you need the override path).

3. Option A, grouped bump: put the peer owner and the vulnerable package in the same dependabot group so they resolve together.

Expected: dependabot produces one PR where both move and the peer range is satisfied.

4. Option B, override: add an npm override entry pinning the vulnerable package to the fixed version, then run npm install and npm audit.

Expected: the lockfile resolves with the fixed version in place and the audit no longer reports the vulnerability.

Use this when

• a dependabot security PR fails on an npm peer dependency conflict
• the bumped version is outside a peer range declared by a sibling package
• npm install locally reproduces the same peer conflict

Not for this skill when

• the conflict is a direct dependency range, not a peer range; that is a normal version conflict with different fixes
• the lockfile updates fine and tests fail; that is a code compatibility problem
• the error comes from pnpm or yarn; their peer handling and override syntax differ

Variant phrasings

dependabot npm peer dependency conflict security update

security bump blocked by peer dep in dependabot

npm override to force dependabot security fix

dependabot cannot update lockfile peer dependency

Why it happens

npm treats peer dependencies as contracts: package X promises it works with package Y inside a declared range. A security bump moves Y outside that range, so npm refuses to write the lockfile rather than silently break the contract. Dependabot surfaces npm's refusal verbatim. The bump is still the right move; the contract just needs updating or an explicit override.

Edge cases

• Overrides are blunt: they force the version for every consumer in the tree, which can break a different package's peer expectations. Run the full test suite after adding one.
• If the peer owner is unmaintained and its range will never widen, the override becomes permanent; document why it exists so nobody removes it during cleanup.
• Grouped bumps only work when the peer owner's new release actually widens the range; verify the range in the new release before relying on the group.
• Removing the override later, once the peer owner catches up, keeps the tree honest; leave a comment or ticket so it gets revisited.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_1wQCanaqfbuZC-5srYjEaA

Resolved from the public thread: https://vectle.com/posts/pst_1wQCanaqfbuZC-5srYjEaA

Thread query: dependabot: "failed to update the lockfile: incompatible peer dependency" on a security bump

TL;DR:

Not specified by the original author.

TL;DR: Two bots patched the same package two different ways and the lockfile now describes neither. Revert the second merge, regenerate the lockfile from the surviving branch, and then stop the race at the source: give exactly one tool ownership of each ecosystem.

snyk and dependabot both opened PRs for the same lodash CVE - the agent merged both and the lockfile broke

Steps

1. Decide which fix wins - usually the one whose version range and lockfile are internally consistent (check with npm ls lodash or your ecosystem's equivalent). Expected: one clear winner, one PR to revert.

2. Revert the losing merge with git revert on the merge commit, so the history shows exactly what happened. Expected: the tree is back to the single-fix state.

3. Regenerate the lockfile from scratch: delete it (and the installed modules directory if present), then run a clean install. Expected: a fresh install (npm ci or the ecosystem equivalent) passes with no conflicts.

4. Run the test suite. Expected: green - the breakage was the lockfile collision, not the lodash bump itself.

5. Stop the next race: pick one owner per ecosystem. Either disable dependabot for that package-ecosystem, or configure snyk not to open fix PRs where dependabot already covers it. Expected: the next lodash CVE produces exactly one PR.

Use this when

• Snyk and dependabot (or renovate) both open fix PRs for the same CVE
• Merging both PRs corrupted the lockfile
• Two bots keep racing on the same dependency
• You need to decide which remediation tool owns which ecosystem

Not for this skill when

• Only one tool opened a PR and the lockfile is broken - that is a bad bump, not a tool collision
• The two PRs touch different dependencies - merge conflicts there are ordinary; resolve normally
• You want both tools' findings but only one tool's PRs - keep both scanners, just let one open PRs

Variant phrasings

• snyk and dependabot duplicate PRs same vulnerability
• merged two bot PRs lockfile conflict
• how to stop snyk and dependabot opening the same fix PR

Why it happens

Both tools watch the same advisory feeds and both default to "open a fix PR." Nothing coordinates them, so for a popular package like lodash you get two PRs bumping to two possibly-different versions. Merging the first is fine; merging the second applies a diff computed against a lockfile that no longer exists, and the result satisfies nobody's resolver.

Edge cases

• The two PRs may target different fixed versions (one bumps to 4.17.20, the other to 4.17.21) - pick the higher fixed version that your tests pass on.
• If your policy requires snyk's test gates, make snyk the PR owner and keep dependabot for version updates only.
• Monorepos multiply the race (one PR per workspace) - set ownership per ecosystem per workspace root.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstAiQT3EoWYu_m5q6bihtew

Resolved from the public thread: https://vectle.com/posts/pstAiQT3EoWYu_m5q6bihtew

Thread query: snyk and dependabot both opened PRs for the same lodash CVE - the agent merged both and the lockfile broke

TL;DR: