nix: Error updating branch: update failure

[biederKdo]

How are you running Renovate?

A Mend.io-hosted app

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

No response

Please tell us more about your question or problem

Running renovate on a nix flake project results in Error updating branch: update failure.

https://github.com/biederKdo/minimal-reproduction-template

Logs (if relevant)

Logs

DEBUG: currentDigest not found in string to replace (branch="renovate/nixpkgs-208.x")
{
  "stringToReplace": "v208"
  "currentDigest": "7819a0d29d1dd2bc331bec4b327f0776359b1fa6"
}

DEBUG: Starting search at index 94 (branch="renovate/nixpkgs-208.x")
{
  "packageFile": "flake.nix"
  "depName": "nixpkgs"
}

DEBUG: Found match at index 94 (branch="renovate/nixpkgs-208.x")
{
  "packageFile": "flake.nix"
  "depName": "nixpkgs"
}

DEBUG: Value is not updated (branch="renovate/nixpkgs-208.x")
{
  "depName": "nixpkgs"
  "manager": "nix"
  "packageFile": "flake.nix"
  "expectedValue": "v208"
  "foundValue": "nixos-24.11"
}

WARN: Error updating branch: update failure (branch="renovate/nixpkgs-208.x")

Full logs: https://gist.github.com/biederKdo/172264bae0cb06988edcf28350acfd0e

[rarkins]

Adding to the logs:

 {
            "depName": "nixpkgs",
            "currentValue": "nixos-24.11",
            "currentDigest": "7819a0d29d1dd2bc331bec4b327f0776359b1fa6",
            "datasource": "git-refs",
            "packageName": "https://github.com/nixos/nixpkgs",
            "updates": [
              {
                "bucket": "major",
                "newVersion": "v208",
                "newValue": "v208",
                "newDigest": "7d3fad345602686eef54ad28e6c3aa7f121eb621",
                "newMajor": 208,
                "newMinor": 0,
                "newPatch": 0,
                "updateType": "major",
                "branchName": "renovate/nixpkgs-208.x"
              },
              {
                "updateType": "digest",
                "newValue": "nixos-24.11",
                "newDigest": "60e405b241edb6f0573f3d9f944617fe33ac4a73",
                "branchName": "renovate/nixpkgs-digest"
              }
            ],
            "versioning": "semver-coerced",
            "warnings": [],
            "sourceUrl": "https://github.com/nixos/nixpkgs",
            "currentVersion": "nixos-24.11",
            "isSingleVersion": true
          }

That v208 seems unlike the existing value (nixos-24.11). Is it an expected new value to update to, or incorrect?

[jalil-salame]

It is a valid tag from nixpkgs, but points to a commit from ~10 years ago

[tebriel]

using semver-coerced is the issue here. use versioning nixpkgs like so (note it'll try to do 25.05 since that branch exists but that release isn't expected until the 23rd)

{
  "nix": { "enabled": true },
  "packageRules": [{
    "matchDatasources": ["nix"],
    "matchDepNames": ["nixpkgs"],
    "versioning": "nixpkgs"
  }]
}

[biederKdo]

Similar result with that config:

DEBUG: Value is not updated (repository=myrepo, packageFile=flake.nix, branch=renovate/nixpkgs-25.x)
       "depName": "nixpkgs",
       "manager": "nix",
       "expectedValue": "nixos-25.05",
       "foundValue": "nixos-24.11"
 WARN: Error updating branch: update failure (repository=myrepo, branch=renovate/nixpkgs-25.x)

[tebriel]

sorry I didn't set expectations correctly. This will just fix the value it tries to update instead of the wrong v208. I haven't been able to get nix updating working. One problem I see in the logs is that sections of the cache are suddenly owned by root. I'm wondering if that's because it's using nix for things and my host that renovate runs on is nix. I need to either trace the code or try running it in a docker to isolate it from the system's nix implementation. Do you see these errors too?

[yellowhat]

I am having similar issue.

Repository: https://github.com/yellowhat/bug-renovate

DEBUG: Setting current branch to main (repository=yellowhat/bug-renovate, branch=renovate/nixpkgs-digest)
DEBUG: latest commit (repository=yellowhat/bug-renovate, branch=renovate/nixpkgs-digest)
       "branchName": "main",
       "latestCommitDate": "2025-05-12T17:42:46Z"
DEBUG: manager.getUpdatedPackageFiles() reuseExistingBranch=false (repository=yellowhat/bug-renovate, branch=renovate/nixpkgs-digest)
DEBUG: currentDigest not found in string to replace (repository=yellowhat/bug-renovate, branch=renovate/nixpkgs-digest)
       "stringToReplace": "nixos-unstable",
       "currentDigest": "979daf34c8cacebcd917d540070b52a3c2b9b16e"
DEBUG: Starting search at index 88 (repository=yellowhat/bug-renovate, packageFile=flake.nix, branch=renovate/nixpkgs-digest)
       "depName": "nixpkgs"
DEBUG: Found match at index 88 (repository=yellowhat/bug-renovate, packageFile=flake.nix, branch=renovate/nixpkgs-digest)
       "depName": "nixpkgs"
DEBUG: Digest is not updated (repository=yellowhat/bug-renovate, packageFile=flake.nix, branch=renovate/nixpkgs-digest)
       "depName": "nixpkgs",
       "manager": "nix",
       "expectedValue": "d89fc19e405cb2d55ce7cc114356846a0ee5e956",
       "foundValue": "979daf34c8cacebcd917d540070b52a3c2b9b16e"
 WARN: Error updating branch: update failure (repository=yellowhat/bug-renovate, branch=renovate/nixpkgs-digest)

[yellowhat]

I am inclined to thing that this is not a nix problem.

$ cat a.sh
# renovate: datasource=docker depName=kindest/node
NODE_VER=v1.33.0

echo "$NODE_VER"

$ cat config.js
...
    packageRules: [
        {
            description: "Pin digest for container image",
            matchDatasources: ["docker"],
            pinDigests: true,
        },
    ],
    customManagers: [
        {
            description: "Comment",
            customType: "regex",
            managerFilePatterns: ["/.*/"],
            matchStrings: [
                "#\\s*renovate:\\s*datasource=(?<datasource>\\S+)\\s+depName=(?<depName>\\S+)\\s*(versioning=(?<versioning>\\S*))?\\s+.*(?i)(tag|ver|version)\\s*(=|:)\\s*(['\"]?)(?<currentValue>[^\"'\\s]*)(['\"]?)",
            ],
            versioningTemplate:
                "{{#if versioning}}{{{versioning}}}{{else}}ver{{/if}}",
        },
    ],
...

Still getting:

WARN: Error updating branch: update failure

[fooker]

I see the same issue. But this seems to be different to what the original issue describes (while still being shown in the log). Maybe this is worth it's own issue?