How can I diff two git branches in bitbucket pipeline

Question

Background

I want to make sure that all commit messages on the pushed branch have a time log in it

ie. add readme /spend 5m

Problem

I want to get the commit diff between two git branches in bitbucket pipeline,

this is my yaml pipeline config:

pipelines:
  default:
    - step:
        script:
          - git log $BITBUCKET_BRANCH --oneline --not master

$BITBUCKET_BRANCH is the branch the pipeline is acting on.

but the pipeline is returning an error when trying to compare with master

+ git log $BITBUCKET_BRANCH --oneline --not master
fatal: ambiguous argument 'master': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

Note that the setup step in the pipeline(this is pre-defined by bitbucket and I can't change it)

git clone --branch="abdullah-s/bitbucketpipelinesyml-created-online-wit-1489917130851" --depth 50 https://x-token-auth:[email protected]/abdullah-s/webook.git $BUILD_DIR;
git reset --hard ac61f080a28428bdd885735374164577a2b0aa43;
git remote set-url origin [email protected]:abdullah-s/webook.git

in the first command of the setup, bitbucket is cloning only one branch from my repo

What I tried

I tried to pull master

- git checkout -b master
- git pull origin master
- git log $BITBUCKET_BRANCH --oneline --not master

but got an error

+ git pull origin master
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.

Question

How can I compare two branches in bitbucket pipeline?

Answer 1

As you rightfully point out, Bitbucket pipelines will only clone the specific branch that triggered the build.

As such, the RefSpec will be set to the specific branch, and you'll be unable to merge or diff other branches.

For example, if the build was triggered on the develop branch, then the following refspec will be set:

[remote "origin"]
    url = [email protected]:xxxxxx
    fetch = +refs/heads/develop:refs/remotes/origin/develop
[branch "develop"]
    remote = origin
    merge = refs/heads/develop

If you look at the available branches you'll see this :

+ git branch -a
* develop
  remotes/origin/develop

You can execute the following command :

git fetch origin "+refs/heads/*:refs/remotes/origin/*"

to pull in all other branches / tags

From bitbucket.org:xxxx/xxxxx
 * [new branch]      master     -> origin/master
 * [new branch]      release    -> origin/release
 * [new tag]         xxxx -> xxxx