Help proxy error: R documentation fails to show

[genec1]

Type: Bug

When trying to get the documentation on a library function in R, I get
Error occurred while trying to proxy: 127.0.0.1:53201/library/DBI/html/dbConnect.html

VS Code version: Positron 1.95.0 (Universal) (bc8820b, 2025-01-09T23:29:00.471Z)
OS version: Darwin arm64 24.2.0
Modes:

System Info

Item	Value
CPUs	Apple M2 Max (12 x 2400)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	6, 6, 6
Memory (System)	96.00GB (27.86GB free)
Process Argv
Screen Reader	no
VM	0%

Extensions (12)

Extension	Author (truncated)	Version
pyright	ms-	1.1.392
debugpy	ms-	2024.14.0
js-debug	ms-	1.96.0
project-manager	ale	12.8.0
ruff	cha	2025.4.0
codeium	Cod	1.30.18
python-environment-manager	don	1.2.7
prettier-vscode	esb	11.0.0
rainbow-csv	mec	3.3.0
shiny	Pos	1.1.0
shinyuieditor	pos	0.5.0
ayu	tea	1.0.3

[juliasilge]

We have definitely had some challenges with the Help proxy in the past! Can you give us a bit more information? For example, does this happen to you every time you bring up Help? Or is it an intermittent problem?

If you can reproduce this (or to get us more information the next time you run into it), can you change the R kernel log level to trace:

And then share the logs from the R Kernel if you see this error again? If you don't know where these logs are, you can find them by:

• Bring up Command Palette
• Search for "Output: Show output channels"
• Choose the one for "R x.y.z: Kernel" where x.y.z is your version
• Copy the entire log and paste it in or upload it as an attachment (.log file) to this issue

You are looking for what happens after a message like:

Sending frontend event ShowHelp with R url 'http://127.0.0.1:24910/library/DBI/html/dbConnect.html' and proxy url 'http://127.0.0.1:50958/library/DBI/html/dbConnect.html'

[genec1]

The issue is not replicating right now. I will report back if it does.

However, I am seeing this related issue:
If I type, for example, ? dbConnect in the Console, the R documentation comes up in the help panel. But if I right click on dbConnect() in my Rmd file, none of the help options work. They all report “No references found for ‘dbConnect’”

[juliasilge]

@genec1 are you trying to bring up Help docs in the Help pane? I don't believe that right-clicking will do that (no Help in the context menu there). Instead I believe that F1 should bring up the Help pane with the correct content. Note that this currently uses your current R session, so you would need to do library(DBI) and then F1 on dbConnect() (similar to how ? behaves).

[genec1]

I've found that the F1 popup help works in a .R file, but it does not work in a .Rmd file.

In a .Rmd file, the code interpreter is confused by back-ticks earlier in the code, in a separate code block.

I have these two code blocks:

# ```{r}
# ... some stuff
ggplot(all_strats_pl, aes(x=date)) +
	geom_line(aes(y= `5delta-600-SL`), col=1) +
	geom_line(aes(y= `15delta-600-SL`), col=2) +
	geom_line(aes(y= `ABC-3-2-LC`), col=3) +
	geom_line(aes(y= `ABC-3-2-LP`), col=4)

#```

#```{r}
con <- dbConnect(duckdb())
# ... some stuff
#```

(I put comments in front of the code block delimiters so that they would be visible in this post)

When I F1 on the dbConnect statement, an alert at the bottom of the screen says:
"No R help available for '), col=3) + geom_line(aes(y= '"

I was having the same issue trying to Ctrl-Return run single lines in the R code block. Ctrl-Returning on the dbConnect statement would enter lines from part of the ggplot statement above, including the code block end and start.

[juliasilge]

I'm not able to reproduce the problem with F1 in an .Rmd with those two chunks in them. Can you create a shareable .Rmd where you see F1 not working and attach it as a file to this issue?

Alternatively, you can use this guide for how to include a Quarto/.Rmd file in a GitHub issue. That page has lots of helpful info on sharing a useful bug report for Quarto/.Rmd!

[genec1]

It was hard to isolate the code section that caused the error. In the end, I needed a big chunk of code above the section where I am reproducing the error. I am attaching an Rmd file (re-named to a .txt file for the upload) where I can reproduce the error. The code probably won't run, since I've removed earlier code chunks.

If I hit F1 on dbConnect in the last code chunk I see the error:

posit_help_error.txt

[juliasilge]

Ah, you need to add a newline at the current line 23 of what you shared. We use Quarto as the engine for parsing .Rmd files and the type of syntax you had like this is not valid:

```r
# r code
```
# A new header that breaks the parsing
```r
# more R code
```

Instead you need this:

```r
# r code
```

# A new header that works fine
```r
# more R code
```

And to be even safer and avoid parsing problems in general, I would recommend this:

```r
# r code
```

# A new header that works fine

```r
# more R code
```

[genec1]

Thanks Julia. Is that in the markdown specs or a peculiarity to the parser in posit?