私の生き方にタイトルなど要らない

You asked me to pull without telling me which branch you want to merge with, 
and 'branch.new_branch.merge' in your configuration file does not tell me, either.
 Please specify which branch you want to use on the command line and try again
 (e.g. 'git pull  '). See git-pull(1) for details.

$ git fetch
$ git checkout -b new_branch
$ git pull origin new_branch

設定方法 1.

$ git branch --set-upstream new_branch origin/new_branch

$ git branch -u origin/new_branch

$ git branch --set-upstream-to=origin/new_branch

$ git branch -u origin/new_branch new_branch

$ git branch --set-upstream-to=origin/new_branch new_branch

設定方法 2.

$ git push -u origin new_branch

設定方法 3.

$ git checkout -b new_branch origin/new_branch

教訓

ブランチ作成後の初回pushの際は-uオプションをつけよう
リモートのブランチを持ってくる際にpullしてくるのはやめよう

$ git branch -a
* pull_req_no_branch
 develop
 master
 remotes/origin/pull_req_no_branch
 remotes/origin/develop
 remotes/origin/master

$ git fetch -p
〜省略〜
   123456..78910  develop    -> origin/develop
 x [deleted]         (none)     -> origin/pull_req_no_branch

$ git branch -a
* pull_req_no_branch
 develop
 master
 remotes/origin/develop
 remotes/origin/master

$ git checkout develop

$ git pull

error: The branch 'pull_req_no_branch' is not fully merged.

$ git branch -d pull_req_no_branch
Deleted branch pull_req_no_branch (was 1234567).

$ git branch -a
* develop
 master
 remotes/origin/develop
 remotes/origin/master

git log --graph --date=short --decorate=short --pretty=format:'%Cgreen%h %Creset%cd %Cblue%cn %Cred%d %Creset%s'

git config --global alias.tr 'log --graph --date=short --decorate=short --pretty=format:"%Cgreen%h %Creset%cd %Cblue%cn %Cred%d %Creset%s"'

git tr