Auto Build breaks if files get changed externally

[tfncp]

Is your feature request related to a problem? Please describe.
I'm working on a multi-file LaTex document and my LaTeX sources are managed in a git repository with multiple branches.
When I switch the git branch, some latex files get changed in the filesystem externally (by git). This unfortunately breaks the auto build feature of Latex Workshop, it is not triggered any more. When I close VS Code and reopen it and everything works fine again.

Describe the solution you'd like
I'd like auto build to automatically detect file changes, additions, deletions, etc. that are caused externally.
Alternatively a key-board shortcut for manually reinitializing the auto build file-watcher / latex workshop would work as well.

[tfncp]

Sorry, I was busy last week, but now I had time to reproduce the behaviour.
For a new test I created a very small demo git repo containing only a latex file main.tex and a simple latexmkrc file in the master. I also created a branch1 in the git repo where I just modified some text in the main.tex file.

With this setup the test is performed like this:

1. I start with the git master branch in my working directory.
2. I open VS code (beginning of log file below) => document get's built and shown in internal pdf viewer.
3. I switch the git branch using git checkout branch1 on an external console window. During the checkout of the branch VS code is still open and the main.tex file is changed.
4. The modified file content is shown in VS code and the modification is automatically recognised by latex workshop (see [10:33:10] in the log). The document is rebuilt. Everything is fine :-)
5. But now at about 10:34:xx I modify the text in main.tex in VS code and I save the file --> nothing happens, no new line in the log is shown.

I can reproduce that behaviour using macOS or windows, I havn't tested in a linux environment.

LaTeX Workshot log output of the described test:

[10:32:29] Initializing LaTeX Workshop.
[10:32:29] Creating file watcher for .pdf files.
[10:32:29] Creating LaTeX Workshop http and websocket server.
[10:32:29] LaTeX Workshop initialized.
[10:32:29] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:32:29] Root file changed from: undefined to /Users/tf/source/latextest/main.tex. Find all dependencies.
[10:32:29] Instantiating a new file watcher for /Users/tf/source/latextest/main.tex
[10:32:29] Creating file watcher for .bib files.
[10:32:29] Parsing /Users/tf/source/latextest/main.tex
[10:32:29] Parse fls file.
[10:32:29] Server created on 127.0.0.1:55673
[10:32:29] Adding /Users/tf/source/latextest/main.tex to file watcher.
[10:32:30] Snippet data loaded.
[10:32:30] LaTeX Workshop version: 8.9.0
[10:32:35] LOG command invoked.
[10:32:35] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:32:35] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:32:40] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:32:40] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:32:40] File watcher: responding to change in /Users/tf/source/latextest/main.tex
[10:32:40] Parsing /Users/tf/source/latextest/main.tex
[10:32:40] Parse fls file.
[10:32:40] /Users/tf/source/latextest/main.tex changed. Auto build project.
[10:32:40] BUILD command invoked.
[10:32:40] Building root file: /Users/tf/source/latextest/main.tex
[10:32:40] Build root file /Users/tf/source/latextest/main.tex
[10:32:40] Recipe step 1: latexmk, -synctex=1,-interaction=nonstopmode,-file-line-error,-pdf,-outdir=/Users/tf/source/latextest,/Users/tf/source/latextest/main
[10:32:40] cwd: /Users/tf/source/latextest
[10:32:40] LaTeX build process spawned. PID: 34602.
[10:32:41] Recipe of length 1 finished. PID: 34602.
[10:32:41] Successfully built /Users/tf/source/latextest/main.tex.
[10:32:43] VIEW command invoked with mode: file:///Users/tf/source/latextest/main.tex.
[10:32:43] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:32:43] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:32:43] Serving PDF file at http://localhost:55673/viewer.html?file=pdf..JTJGVXNlcnMlMkZ0ZiUyRnNvdXJjZSUyRmxhdGV4dGVzdCUyRm1haW4ucGRm
[10:32:43] The encoded path is /Users/tf/source/latextest/main.pdf
[10:32:43] Open PDF tab for /Users/tf/source/latextest/main.pdf
[10:32:44] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:32:44] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:32:44] Handle data type: open
[10:32:44] Preview PDF file: /Users/tf/source/latextest/main.pdf
[10:32:44] Handle data type: request_params
[10:32:45] Handle data type: loaded
[10:33:10] File watcher: responding to change in /Users/tf/source/latextest/main.tex
[10:33:10] Parsing /Users/tf/source/latextest/main.tex
[10:33:10] Parse fls file.
[10:33:10] /Users/tf/source/latextest/main.tex changed. Auto build project.
[10:33:10] BUILD command invoked.
[10:33:10] Building root file: /Users/tf/source/latextest/main.tex
[10:33:10] Build root file /Users/tf/source/latextest/main.tex
[10:33:10] Recipe step 1: latexmk, -synctex=1,-interaction=nonstopmode,-file-line-error,-pdf,-outdir=/Users/tf/source/latextest,/Users/tf/source/latextest/main
[10:33:10] cwd: /Users/tf/source/latextest
[10:33:10] LaTeX build process spawned. PID: 34649.
[10:33:12] LaTeX log parsed with 1 messages.
[10:33:12] Recipe of length 1 finished. PID: 34649.
[10:33:12] Successfully built /Users/tf/source/latextest/main.tex.
[10:33:12] Refresh PDF viewer for /Users/tf/source/latextest/main.pdf
[10:33:12] Parse fls file.
[10:33:12] Preview PDF file: /Users/tf/source/latextest/main.pdf
[10:33:12] Handle data type: loaded
[10:33:24] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:33:24] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:33:39] LOG command invoked.
[10:33:39] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:33:39] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:49:40] LOG command invoked.
[10:57:44] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:57:44] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:57:52] LOG command invoked.
[10:57:53] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:57:53] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.
[10:57:55] Found root file from active editor: /Users/tf/source/latextest/main.tex
[10:57:55] Root file remains unchanged from: /Users/tf/source/latextest/main.tex.

[tamuratak]

Set latex-workshop.latex.watch.usePolling: true. See https://github.com/James-Yu/LaTeX-Workshop/wiki/Compile#latex-workshoplatexwatchusepolling

[jlelong]

Well, I believe this is related to paulmillr/chokidar#237

The issue is that git checkout actually changes the inode of the file. Right after the git checkout, chokidar catches a rename event, which we do not handle for now and then a change event.

Adding

            this.fileWatcher.on('raw', (type, _filename, details) => {
                if (type === 'rename') {
                    this.fileWatcher?.unwatch(details.watchedPath)
                    this.fileWatcher?.add(details.watchedPath)
                }
            })

seems to fix everything.

[tamuratak]

I am not sure whether the code works fine on all the platforms. The word, raw, is equal to danger here. I think setting latex-workshop.latex.watch.usePolling: true by default is a simple solution.

[jlelong]

I am not sure whether the code works fine on all the platforms

I also fear this. I had the impression that using polling was a kind of last resort but if it works, let us just leave it like this. Maybe we could ask the chokidar guys if they have a suggestion.