The jenkins console after I try to git merge before build

git-merge-before-build.log

[Pipeline] checkout
 > git rev-parse --is-inside-work-tree # timeout=10
Fetching changes from the remote Git repository
 > git config remote.origin.url /tmp/jenkins/upstream-repo # timeout=10
Fetching upstream changes from /tmp/jenkins/upstream-repo
 > git --version # timeout=10
 > git -c core.askpass=true fetch --tags --progress /tmp/jenkins/upstream-repo pull-requests/1/from
 > git rev-parse refs/remotes/origin/master^{commit} # timeout=10
 > git rev-parse refs/remotes/origin/refs/heads/master^{commit} # timeout=10
Merging Revision 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f (refs/remotes/origin/master) to origin/master, UserMergeOptions{mergeRemote='origin', mergeTarget='master', mergeStrategy='MergeCommand.Strategy', fastForwardMode='--no-ff'}
 > git rev-parse origin/master^{commit} # timeout=10
 > git config core.sparsecheckout # timeout=10
 > git checkout -f origin/master # timeout=10
 > git branch -a -v --no-abbrev # timeout=10
 > git branch -D master # timeout=10
 > git checkout -b master origin/master
 > git merge --no-ff 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f # timeout=10
 > git rev-parse HEAD^{commit} # timeout=10
Seen branch in repository origin/HEAD
Seen branch in repository origin/master
Seen branch in repository origin/pull-requests/1/from
Seen 3 remote branches
Checking out Revision 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f (origin/master, origin/master)
 > git config core.sparsecheckout # timeout=10
 > git checkout -f 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f # timeout=10
 > git branch -a -v --no-abbrev # timeout=10
 > git branch -D master # timeout=10
 > git checkout -b master 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f
 > git rev-list 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f # timeout=10
 > git rev-list 19e39345b1b178e3ebc4c5b3af277cbd64c37f9f # timeout=10
[Pipeline] sh
[workspace] Running shell script
+ git log -n 10 --graph --pretty=oneline --abbrev-commit --all --decorate=full
* 3644c2e (refs/remotes/origin/pull-requests/1/from, refs/remotes/origin/HEAD, refs/heads/pull-requests/1/from) Add file
* 19e3934 (HEAD -> refs/heads/master, refs/remotes/origin/master) init
[Pipeline] } //node
[Pipeline] Allocate node : End
[Pipeline] End of Pipeline