Git fetch can't pull some branches?

think git checkout xxx Times wrong: error: pathspec "xxx" did not match any file (s) known to git. then after git fetch, use git branch-a to check, there are many branches, but there is still no xxx this. Could you tell me how to deal with this?

Git
Dec.01,2021

git checkout-b origin/xxx

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-7c1f10-28f16.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-7c1f10-28f16.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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