How to configure the R interpreter?

[apalacio9502]

Hi,

I've been trying out this new IDE, and for Python, Positron detects the interpreter correctly. However, it doesn't detect the R interpreter.

When I run R --version in the console, the system detects the R version without any issues.

It is important to mention that R is installed in a non-default path, and the PATH configured in the environment variables is: "C:\Users\apalacio\Documents\R\R-4.4.0\bin\x64".

Is there anything else that needs to be configured?

Regards,

[slodge]

Same question here.

We can't use the standard C:\program files\R path for R because of our machines network and admin config - so we use a C:\apps\R path instead. RStudio picks these up fine - but I can't see how to tease Positron into picking the interpreters up.

[janjwesselink]

Hi, I'm facing the same issue on Linux Mint (v21.3) and my R installation is just under /usr/bin/R (v.4.1.2) any help would be much appreciated.,
Best,
Jan-Jaap

[jennybc]

In your case @janjwesselink, the problem is that Positron only supports R >= 4.2.

If you look in the output channel for the Positron R Extension, you will presumably see that your R installation is being discovered, as it's in one of the standard locations we check. But then it's being discarded due to not being recent enough.

[jmcphers]

Positron reads the system registry to discover R versions. R typically writes to the registry when it's installed. If you manually installed R to a different location, you can add a couple of registry keys to point Positron in the right direction. They're documented here:

https://cran.r-project.org/bin/windows/base/rw-FAQ.html#Does-R-use-the-Registry_003f

It's reasonable to expect Positron to pick up anything on the $PATH, though, as RStudio does. I think it does this today for Linux and macOS, but not yet Windows. I'll file an issue for us to look at. Thanks for reporting!

[jmcphers]

Issue here, feel free to add some color: #3702

[slodge]

I'm unsure if this registry reading is working correctly

Here's a view form my regedit

But positron not showing R:

While RStudio shows options:

It's possible something else has gone wrong here (we did have some extra R installations recently caused by over enthusiastic IT help), but certainly positron isn't showing those options that are in the registry - and there doesn't seem to be any way to add a manual choice.

[slodge]

I'll try a reboot over the weekend - let's see if Windows just needs a reset...

[apalacio9502]

Hi,

I believe we might be facing a bug because when the installation is done in a custom path, the installer correctly adds the registry keys.

I have checked the registry keys and see entries for all the versions of R that I have installed, from 4.3.1 to 4.4.1.

According to the shared documentation, these entries are correctly defined.

Regards,

[jennybc]

@slodge We consult the keys in R-core/R64 as opposed to R-core/R. Can you show what you see there?

(Whether we can stick with this strong prioritization of explicitly 64-bit artefacts is obviously another question.)

[slodge]

They match the equivalent values as the 32-bit ones

(Fine by me if you stick with 64-bit !)

[DavisVaughan]

In particular if you click directly on the R64 folder and take a screenshot at that point, we'd like to see if there is an InstallPath value at that point

[slodge]

Here?

No

[slodge]

(Each version of R was installed via normal installer... just the install path is changed each time)

[DavisVaughan]

It would also be very helpful if one of you could do this:

Can you please copy and paste in your full Positron R Extension output logs? You can get there by hitting Cmd + P to pull up the command palette, typing in Output: Show Output Channels..., and clicking on Positron R Extension.

[jennybc]

I'm confused.

This screenshot (#3677 (reply in thread)) shows HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.3.0 as having an InstallPath with string value C:\Source\R\R-4.3.0 and (I think?) it does not get discovered (?).

Then just above you say:

By manually adding an InstallPath string value at that R64 level I can get Positron to pick up one R version

Can you give the precise "working (gets discovered)" vs. "not working (does not get discovered)" between the 2 cases?

[slodge]

Nothing is discovered until I manually added an InstallPath value directly at the R64 level (I tried this after the request from @DavisVaughan)

Can you give the precise "working (gets discovered)" vs. "not working (does not get discovered)" between the 2 cases?

These reg keys added over the last year by the R installers are not found by Positron:

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.2.0]
"InstallPath"="C:\\source\\R\\R-4.2.0"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.3.0]
"InstallPath"="C:\\Source\\R\\R-4.3.0"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.4.1]
"InstallPath"="C:\\Source\\R\\R-4.4.1"

This string value manually added by me (in the existing R64 reg key) 20 minutes ago is discovered:

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64]
"InstallPath"="C:\\Source\\R\\R-4.4.1"

[jennybc]

Thanks, this is helpful.

Can you say more about how your R installation(s) come to be the way they are? I don't have my Windows VM up right now, but your situation seems to differ from what I have been experiencing, so I'm guessing we install R in different ways. And you are an actual Windows user, whereas I am just faking it 😂

Do you use the CRAN installer? I think I have mostly installed R on Windows using rig.

[no-more-hacks]

I have a similar issue, I only see versions of R that are installed in the default location. I used the installer but used a NON default location, I have many versions of R installed, and RStudio can see them all.

To try and get Positron to pick up the R version that I wanted, I edited the key that slodge mentioned to point to an older R version that is NOT installed in the default location:

(yes I can see that my install path and version don't match now)

and now i have this:

so it "worked" in the sense that i now have the version of R that i wanted, but strangely i still have the install of 4.4. Maybe it's reading the reg key AND looking in the "program files" location on disk.

[juliasilge]

We've got #3787 where we are tracking improvements in this area.

[apalacio9502]

Hello,

I believe my case is a bit different, as in my situation the registry keys are correct. It is important to highlight that I install the R versions using the CRAN installer, only changing the installation path.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core]

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.1"
"Current Version"="4.4.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\4.3.1]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\4.3.2]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.2"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\4.3.3]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.3"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\4.4.0]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.0"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\4.4.1]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.1"
"Current Version"="4.4.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.3.1]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.3.2]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.2"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.3.3]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.3.3"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.4.0]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.0"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\4.4.1]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.1"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\Rtools]
"InstallPath"="C:\\rtools44"
"Current Version"="4.4.6104"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\Rtools\4.3.5863]
"InstallPath"="C:\\rtools43"
"FullVersion"="4.3.5863.5818"

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\Rtools\4.4.6104]
"InstallPath"="C:\\rtools44"
"FullVersion"="4.4.6104.6039"

Regarding my specific case, according to the logs, it seems that Positron is trying to modify the registry when making the query, which the system does not allow because, in my case, it is blocked by company policies. From my point of view, this is very common.

The translation of this "ERROR: el administrador ha deshabilitado la modificaci�n del Registro." into English is "ERROR: The administrator has disabled registry modification."

2024-06-28 19:26:38.399 [info] Log level: Debug
2024-06-28 19:26:38.399 [info] Refreshing testthat status
2024-06-28 19:26:38.400 [info] Not working in an R package
2024-06-28 19:26:38.400 [info] Context key 'testthatIsConfigured' is 'false'
2024-06-28 19:26:38.400 [info] Context key 'testthatHasTests' is 'false'
2024-06-28 19:26:38.429 [info] Checking for 'InstallPath' in registry key \Software\R-Core\R64 for hive HKCU
2024-06-28 19:26:38.640 [info] Unable to get value of 'InstallPath': QUERY command exited with code 1:

ERROR: el administrador ha deshabilitado la modificaci�n del Registro.
2024-06-28 19:26:38.663 [info] Checking for 'InstallPath' in registry key \Software\WOW6432Node\R-Core\R64 for hive HKCU
2024-06-28 19:26:38.866 [info] Unable to get value of 'InstallPath': QUERY command exited with code 1:

ERROR: el administrador ha deshabilitado la modificaci�n del Registro.
2024-06-28 19:26:38.891 [info] Checking for 'InstallPath' in registry key \Software\R-Core\R64 for hive HKLM
2024-06-28 19:26:39.123 [info] Unable to get value of 'InstallPath': QUERY command exited with code 1:

ERROR: el administrador ha deshabilitado la modificaci�n del Registro.
2024-06-28 19:26:39.146 [info] Checking for 'InstallPath' in registry key \Software\WOW6432Node\R-Core\R64 for hive HKLM
2024-06-28 19:26:39.547 [info] Unable to get value of 'InstallPath': QUERY command exited with code 1:

ERROR: el administrador ha deshabilitado la modificaci�n del Registro.

Regards,

[jennybc]

Positron does not try to modify the registry -- it just tries to read it:

positron/extensions/positron-r/src/provider.ts

Lines 386 to 418 in c929d52

	async function getRegistryInstallPath(hive: string, wow?: string | undefined): Promise<string | undefined> {
	try {
	const key = new winreg({
	hive: hive as keyof typeof winreg,
	// 'R64' here is another place where we explicitly ignore 32-bit R
	// Amend a WOW path after "Software" if requested
	key: `\\Software\\${wow ? wow + '\\' : ''}R-Core\\R64`,
	});
	LOGGER.info(`Checking for 'InstallPath' in registry key ${key.key} for hive ${key.hive}`);
	const result = await new Promise<{ value: string }>((resolve, reject) => {
	key.get('InstallPath', (error, result) => {
	if (error) {
	reject(error);
	} else {
	resolve(result);
	}
	});
	});
	if (!result || typeof result.value !== 'string') {
	LOGGER.info(`Invalid value of 'InstallPath'`);
	return undefined;
	}
	return result.value;
	} catch (error: any) {
	LOGGER.info(`Unable to get value of 'InstallPath': ${error.message}`);
	return undefined;
	}
	}

But I can only assume this is just a misleading error message and it is Positron's attempt to read the registry that is triggering the error (?).

I'm surprised you can inspect these registry keys, if things are this locked down. Did you have to sign in as administrator or similar?

What happens if you define InstallPath like so:

[HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64]
"InstallPath"="C:\\Users\\apalacio\\Documents\\R\\R-4.4.1"
"Current Version"="4.4.1"

but for the current user instead of (in addition to, really) the local machine:

[HKEY_CURRENT_USER\SOFTWARE\R-core\R64]

?

[apalacio9502]

I'm surprised you can inspect these registry keys, if things are this locked down. Did you have to sign in as administrator or similar?

In fact, to obtain these records you have to log in with the computer's administrator user.

[apalacio9502]

but for the current user instead of (in addition to, really) the local machine:

I don't think this is possible, because with my user account, you cannot access the registry keys. Even if the administrator user edits it, the changes would only apply to that user.

[apalacio9502]

Positron does not try to modify the registry -- it just tries to read it:

It's interesting that this error occurs, as other applications that use registry keys don't encounter any issues. For example, the computer has ODBC keys located at HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBCINST.INI, and I can access them with my user account using the R ODBC library's odbc::odbcListDrivers() function.

[jennybc]

As for this point about odbc, I checked with @simonpcouch who has worked on it lately and also poked around the source. I don't think the R package is really responsible for accessing the registry, rather some external tool is doing it:

we generally don’t run into as many configuration issues with Windows users since Windows is bundled with a GUI that takes care of setting registry keys in odbcinst.ini and friends

[jennybc]

but for the current user instead of (in addition to, really) the local machine:

I don't think this is possible, because with my user account, you cannot access the registry keys. Even if the administrator user edits it, the changes would only apply to that user.

This sort of answer is what gives / gave me hope that you should be able to edit entries below HKEY_CURRENT_USER:

https://stackoverflow.com/q/53135

As for different tools having different levels of access to the registry, one hypothesis is that it comes from how they access the registry. Positron is using an npm module (winreg) and, all things considered, I think this is preferred to shelling out, e.g. calling reg query or the like. But that could explain differences in edge case behaviour.

These registry keys are basically the official way to advertise R installations on Windows, so it's unfortunate that your company policies make the registry effectively unreadable for certain methods of access.

https://cran.r-project.org/bin/windows/base/rw-FAQ.html#Does-R-use-the-Registry_003f-1

Note this sentence, which also suggests that you should be able to set entries below HKEY_CURRENT_USER:

After installation you can add the Registry entries by running RSetReg.exe in a sub-folder of the bin folder, and remove them by running this with argument /U. Note that this requires administrative privileges unless run with argument /Personal and neither sets up nor removes the file associations.

My main summary of this discussion is that we should pick up on an R executable on the PATH for Windows (which we're already tracking in #3702).

[slodge]

Underneath winreg is shelling out anyway? https://github.com/fresc81/node-winreg/blob/6d97e9bb2ac54605096e01013527aaa7070b149e/lib/registry.js#L612

Not had a chance to investigate this properly here... sorry! ... but it definitely would be "nice" if positron picked up all the R interpreters that RStudio does 👍

[jennybc]

Interesting!

I did switch positron-r over to use vscode-windows-registry to access the Windows registry, since it would seem a very good fit for us: "This module only has what is needed to support VS Code and is intended to be a lightweight module."

#2410

But then that caused a webpack problem that we decided to not troubleshoot at that time. Perhaps this story is a good reason to revisit that and try harder to sort out the problem we saw in CI.

[apalacio9502]

Hi,

Finally, for it to work, the administrator had to exclude my user account from the Active Directory policy, and with that, it worked.

Now I have a question: if I have several versions of R installed that are correctly registered in the registry keys, why does it only recognize R 4.4.1?

Regards,

[jennybc]

Basically bullet point 2 in #3787. We don't currently use the Windows registry for general R installation discovery. At the moment, we do that in the "usual" places. Then we consult the registry only for the more narrow matter of determining which version of R is current.

[skthewimp]

I'm facing hte same issue in my Mac. Been using RStudio for ages now (and it's been working great) but Positron is just not able to find the R interpreter.

I added "/usr/local/bin/R" (where R is installed) into my path, but still not picking up.

[juliasilge]

This discussion has mostly been about problems with the Windows registry. Do you mind opening a new discussion or issue so we can get details from you?

[skthewimp]

yes. please check: #3832

[TorHenrikUlsted]

I know the developers are working on a fix and will likely fix this issue soon. But for those who want to try Positron out before that, I will add a fix that worked for me on Windows. The issue seem to be related to where positron is looking for the "InstallPath" String value in the Registry editor. I added a link to the PDF file as well as images of it.
detect-non-standard-r-installation-for-positron.pdf

[harlananelson]

I appreciate having a fix. I wish I could get it working. Unfortunately, my system is set as you specify with the InstallPath at the R64 level pointing to the r location: D:\Program Files\R-4.4.1. But neither python nor R works. But it does show that it is searching for the correct version (4.4.1) .

Positron R shows the correct location.

024-08-06 10:26:21.164 [info] Identified the current version of R from the registry: D:\Program Files\R-4.4.1\bin\x64\R.exe
2024-08-06 10:26:21.165 [info] Candidate R binary at D:\Program Files\R-4.4.1\bin\x64\R.exe
2024-08-06 10:26:21.165 [info] R installation discovered: {
  "valid": true,
  "supported": true,
  "binpath": "D:\\Program Files\\R-4.4.1\\bin\\x64\\R.exe",
  "homepath": "D:\\Program Files\\R-4.4.1",
  "semVersion": {
    "options": {},
    "loose": false,
    "includePrerelease": false,
    "raw": "4.4.1",
    "major": 4,
    "minor": 4,
    "patch": 1,
    "prerelease": [],
    "build": [],
    "version": "4.4.1"
  },
  "version": "4.4.1",
  "arch": "x86_64",
  "current": true,
  "orthogonal": true
}

I can also start R from the terminal

$ R

R version 4.4.1 (2024-06-14 ucrt) -- "Race for Your Life"
Copyright (C) 2024 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

  Natural language support but running in an English locale

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

>

Error message after trying to start the R Console

The terminal process "d:\Program Files\Positron\resources\app\extensions\jupyter-adapter\resources\kernel-wrapper.bat 'C:\Users\hnelson3\AppData\Local\Temp\3\kernel-zkQ7MM\kernel.log', 'd:\Program Files\Positron\resources\app\extensions\positron-r\resources\ark\ark.exe', '--connection_file', 'C:\Users\hnelson3\AppData\Local\Temp\3\kernel-zkQ7MM\connection.json', '--log', 'C:\Users\hnelson3\AppData\Local\Temp\3\kernel-zkQ7MM\kernel.log', '--startup-file', 'd:\Program Files\Positron\resources\app\extensions\positron-r\resources\scripts\startup.R', '--session-mode', 'console', '--', '--interactive', '--no-restore-data'" terminated with exit code: 1.

[jennybc]

@harlananelson I recommend that you open a new issue or question, as yours is clearly different from the bulk of what's discussed here. R discovery seems to be working as intended for you but there's trouble in the Jupyter adapter.

[juliasilge]

@harlananelson When I had trouble with the Jupyter adapter on Windows it was failing because of a glibc error. The fix is to make sure you have the latest Visual C++ Redistributable installed:
https://github.com/posit-dev/positron/wiki#windows-prerequisites

[janjwesselink]

Excuse me Jennifer, but I don't understand: I am using R v 4.2.1. (as mentioned ). I should also have mentioned that I installed positron v 2025.07.0 build 125 (the latest I saw) Best, Jan - Jaap Sent from Proton Mail Android

…

-------- Original Message --------

On 8/6/24 16:57, Jennifer (Jenny) Bryan wrote: In your case ***@***.***(https://github.com/janjwesselink), the problem is that Positron only supports R >= 4.2. If you look in the output channel for the Positron R Extension, you will presumably see that your R installation is being discovered, as it's in one of the standard locations we check. But then it's being discarded due to not being recent enough. — Reply to this email directly, [view it on GitHub](#3677 (reply in thread)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/AFOIORV52DVKQHK52Q5BGF3ZQDP4HAVCNFSM6AAAAABKBDGRYWVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTAMRVGQ4TKMA). You are receiving this because you were mentioned.Message ID: ***@***.***>

[jennybc]

Hi, I'm facing the same issue on Linux Mint (v21.3) and my R installation is just under /usr/bin/R (v.4.1.2) any help would be much appreciated.,

☝️ indicates version 4.1.2?

[janjwesselink]

I can't see anything related in Positron, also there is no R under the "start interpreter" button (I could start Python, but want/need R for now :) )
Thanks again for any help you could offer.

[jmcphers]

Positron needs R >= 4.2; it isn't finding these versions since they are too old. Are you able to install a newer R?

[janjwesselink]

Oh dear, I read to quickly.. apologies! I was able to install R 4.4.1 by adding the CRAN repository (for Ubuntu) and it seems to be working now (I was able to start the interpreter in Positron). Sorry for being a nuisance and thanks for the help!

[kkedji]

Hi everyone,
I went through the thread and tried each proposed solution, but Positron doesn't pick R interpreter. I am very new to R and Positron and have just installed both of them today. Here is a screenshot below. Can I please get a help on this?

[jennybc]

@kkedji You are probably another case of what's described in #4280. I suspect the PR that made it possible to discover R on the PATH on Windows is causing it not to be discovered in other ways, for some subset of users. I am hoping someone can provide logs for us to compare in two adjacent versions of Positron, i.e. before and after the regression.

[kkedji]

Hi @jennybc , following your last instructions on #4280 to add the Path environment variable, I am able to see the R interpreter now.

[keitheleejr]

@jennybc I have the same problem. #4280 aligns with the issues I have with the current release. I rolled back to the previous version and the R interpreter is available. I'll gladly share logs for the two adjacent versions if you can provide some direction.

[jennybc]

@keitheleejr I will continue the effort to get logs from someone in #4280.

[keitheleejr]

@jennybc I can do that. I forgot you linked to the wiki for directions. I just took a screenshot of my logs for 2024.07.0-125. I'm currently installing the current release. I'll post the logs in #4280.

[mrjc42]

FWIW, I have this issue b/c my organization requires R be installed to User's folders (we are not allowed to install as administrator). So I guess I will have to wait for a patch unless by some miracle the forgot to turn off my registry editing abilities?

Anyhow, another thing that I wanted to mention is that a LOT of people who run windows these days will also run WSL. So that begs the question: are there any plans to have Positron find THOSE environments?

[jmcphers]

This issue tracks the ability to specify the R location manually for cases like this: #2235

There is currently not support for finding R/Python in WSL. Those environments will not be discovered as peers of other R installations on your system; instead, you'll need to connect Positron itself to WSL so that the rest of your IDE (e.g. the file explorer) shows the WSL context. This issue tracks the work to connect to WSL: #4366.

[niheaven]

Is there any way to specify R path explicitly? Since I'm using scoop to maintain my R installation, there's no registry for it and R.exe is just a shim outside R's installation dir. As in RStudio, I could point R interpreter to actual R dir, but could not find this setting in Positron now.

R Extension's output:

2024-08-29 13:56:29.921 [info] Possibly found R on PATH: D:\Scoop\shims\R.EXE.
2024-08-29 13:56:29.921 [info] Can't determine R_HOME_DIR from the path to the R binary: D:\Scoop\shims\R.EXE
2024-08-29 13:56:29.921 [info] Failed to get R home path from D:\Scoop\shims\R.EXE.

[juliasilge]

That work is tracked in #2235, if you would like to subscribe to that issue.

[niheaven]

Great! Hope the feature will be completed sooner or later.

[kramerrs]

I also have this problem. I take it that my version of R is too old though:

In RStudio I get this.

R.home()
[1] "C:/PROGRA1/R/R-401.3"

[juliasilge]

You can read about the R requirements here: https://github.com/posit-dev/positron/wiki#r-prerequisites

Positron requires R 4.2 or higher.