# Rtools not properly detected in R3.6.0 under Windows 10
**URL:** https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075
**Category:** General
**Created:** [June 3, 2019, 1:49pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075 "2019-06-03T13:49:54Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Seb](https://discourse.mc-stan.org/u/Seb)
#### Post date: [June 3, 2019, 1:49pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/1 "2019-06-03T13:49:54Z")
Dear stan users,
I had problems installing rstan (2.18.2) under R 3.6.0 on a Windows 10 machine by following the [default instructions](https://github.com/stan-dev/rstan/wiki/RStan-Getting-Started).
The problem was with Rtools3.5. Although the line:
```
pkgbuild::has_build_tools(debug = TRUE)
```
returned `TRUE` as it should, the tool chain was not working.
After some foul language, some googling and a few hours lost I found and fixed the problem. In order to save other people from losing time I thought I just post my solution in one place.
1. Unlike indicated in the installing instructions, Rtools needs to be included in the system path like so:
2. The Makevars.win file need to include the line
```
CXX14=$(BINPREF)g++ -O2 -march=native -mtune=native
```
That’s all, hope it helps.
Seb
---
### Author:  [@increasechief](https://discourse.mc-stan.org/u/increasechief)
#### Post date: [June 3, 2019, 1:52pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/2 "2019-06-03T13:52:53Z")
This fix almost deserves a PSA.
---
### Author:  [@jonah](https://discourse.mc-stan.org/u/jonah)
#### Post date: [June 3, 2019, 10:45pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/3 "2019-06-03T22:45:05Z")
Sorry for the headache and thanks for sharing the fix that worked for you.
I don’t have Windows so can’t check for myself, maybe @bgoodri or @paul.buerkner can confirm? We definitely need to change the instructions if this is not some weird special case.
---
### Author:  [@bgoodri](https://discourse.mc-stan.org/u/bgoodri)
#### Post date: [June 3, 2019, 10:56pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/4 "2019-06-03T22:56:27Z")
We just need to get a new rstan onto CRAN.
---
### Author:  [@paul.buerkner](https://discourse.mc-stan.org/u/paul.buerkner)
#### Post date: [June 4, 2019, 7:14am UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/5 "2019-06-04T07:14:50Z")
Thanks! One question: In (1), you write about “sys\_path”, but this does not seem to be the full line you added to the system path, right?
---
### Author:  [@Seb](https://discourse.mc-stan.org/u/Seb)
#### Post date: [June 4, 2019, 7:34am UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/6 "2019-06-04T07:34:23Z")
Thanks for all the responses. As for the system path vars, I manually added:
`C:\Rtools\bin;C:\Rtools\mingw_64\bin`
Actually these might be added automatically by ticking a box in one of the installer windows: 
---
### Author:  [@Gio\_C](https://discourse.mc-stan.org/u/Gio_C)
#### Post date: [June 11, 2019, 5:30pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/7 "2019-06-11T17:30:52Z")
Had the exact same problem - solved it for me as well. Many thanks, Seb.
It took me HOURS to get to a solution - what is the problem with R 3.6, Rtools, and Stan not playing well with each other? I’d like to try and avoid these issues at work in the future, as it caused considerable downtime for my team.
---
### Author:  [@Jonathan\_Mitchell](https://discourse.mc-stan.org/u/Jonathan_Mitchell)
#### Post date: [June 11, 2019, 6:58pm UTC](https://discourse.mc-stan.org/t/rtools-not-properly-detected-in-r3-6-0-under-windows-10/9075/8 "2019-06-11T18:58:50Z")
I’ve been fighting with conflicts resulting from updating to R 3.6 for days now. Specifically, when fitting models using brms that include group variables, my R just dies without a message. rstanarm functions seem to work fine, though.
Just tried this, and it still isn’t working properly for me, unfortunately. It seems a lot of people are having this 3.6/rstan/Windows 10 conflict.