Build server error merge conflict

I build successfully at my computer and push to the build server.
However, the build server fails to build.
The build server log is:

HEAD is now at 85262fd8 Merge remote-tracking branch 'origin/myfeature50'
end reset
start pull
	f6a17689..72034e9f   S2 -> origin/S2
Auto-merging src/
CONFLICT (content): Merge conflict in src/
Automatic merge failed; fix conflicts and then commit the result.
end pull

git log at my computer:

72034e9f Fix bug
f6a17689 Merge remote-tracking branch 'origin/myfeature200' into S2
85262fd8 Merge remote-tracking branch 'origin/myfeature50' into S2

The build server seems to keep pulling from remote-tracking branch ‘origin/myfeature50’
The build server use gitea.
How to fix this build server problem?

Will this work at my computer?

git checkout myfeature50
git rebase myfeature200
//resolve conflict
git add
git commit
git push