Running code line-by-line (Cntrl + Enter) feels extremely laggy in Positron (Slurm Posit WB)

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

Hi, we are using Posit WB on AWS-deployed Slurm cluster.

Running R code line-by-line using Cntrl + Enter in Positron works normally in .R scripts, but when we try to run the code from RMarkdown / Quatro documents, it starts to lag heavily. It also produces bunch of temporary local .vdoc files.

At the same time, in RStudio, everything works normally.

Here is an example when run line-by-line.

> tictoc::tic()
> 1+1
[1] 2
> tictoc::toc()
4.84 sec elapsed

When we select the whole chunk, it works instantly.

> tictoc::tic()
+ 1+1
+ tictoc::toc()
[1] 2
0.002 sec elapsed

Any ideas on what we might try here?

Thanks

Steps to reproduce

No response

Actual behavior

No response

Expected behavior

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Your environment

No response

Quarto check output

Quarto 1.9.37
[✓] Checking environment information...
      Quarto cache location: /pfs/home/.cache/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.8.3: OK
      Dart Sass version 1.87.0: OK
      Deno version 2.4.5: OK
      Typst version 0.14.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.9.37
      Path: /usr/lib/rstudio-server/bin/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: v2024.07.03
      Chromium: (not installed)
      Chrome Headless Shell: (not installed)
      VeraPDF: (not installed)

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /pfs/home/.TinyTeX/bin/x86_64-linux
      Version: 2024

[✓] Checking Chrome Headless....................OK
      Chrome:  (not detected)

[✓] Checking basic markdown render....OK

[✓] Checking R installation...........OK
      Version: 4.4.1
      Path: /opt/R/4.4.1/lib/R
      LibPaths:
        - /pfs/home/.cache/R/renv/sandbox/linux-ubuntu-jammy/R-4.4/x86_64-pc-linux-gnu/22bdb599
      knitr: 1.51
      rmarkdown: 2.31

[✓] Checking Knitr engine render......OK

[✓] Checking Python 3 installation....OK
      Version: 3.10.12
      Path: /usr/bin/python3
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking Julia installation...

Start by reproducing the Ctrl+Enter behavior in Positron with an RMarkdown or Quarto document, comparing line-by-line execution with whole-chunk execution and observing the temporary .vdoc files. The issue names no repository files or tests, so trace the document execution entry point first. Done means identifying the source of the lag and confirming responsive line-by-line execution without unintended temporary files.