Git:`stash`不会找到本地更改,但`pull`会找到它们

我正试图使用Github Actions自动部署我的项目。工作流程是这样的:

    git stash
    git stash drop
    git pull
    # install dependencies and ...

当执行前两行时,git找不到任何局部更改:

    out: No local changes to save
    err: No stash entries found.

但之后 git pull 运行时,会发生以下情况:

    err: From https://github.com/*****/*****
    err:  * branch            main       -> FETCH_HEAD
    err:  ****..****          main       -> origin/main
    err: error: The following untracked working tree files would be overwritten by merge:
    err:    thefile
    err: Please move or remove them before you merge.
    err: Aborting

为什么会这样?