A preview of Rtools 4.0

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# <code>A preview of Rtools 4.0</code>
## <code>rstudio::conf(2019L)</code>
### <code>Jeroen Ooms</code>
### <code>2019/01/18</code>

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# Hello World

![team](team.png)

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# The rOpenSci (extended) Family

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# CRAN Packages

[![pkgscreen](packages2.png)](https://cran.r-project.org/web/checks/check_results_jeroen_at_berkeley.edu.html)

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# Maintainer of Windows Installers

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# PART I: Status Quo of Rtools

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# What is Rtools

Windows does not have a native compiler or package manager:

<table>
  <tr>
    <th></th>
    <th>Native Compiler</th>
    <th>Package Manager</th>
    <th>Linking</th>
  </tr>
  <tr>
    <th>Linux</th>
    <td>yes</td>
    <td>yes</td>
    <td>dynamic</td>
  </tr>
  <tr>
    <th>MacOS</th>
    <td>yes</td>
    <td style="color: red;">no</td>
    <td>static</td>
    <td></td>
  </tr>
  <tr">
    <th>Windows</th>
    <td style="color: red;">no</td>
    <td style="color: red;">no</td>
    <td>static</td>
  </tr>
</table>

So we need to provide our own.

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# What is Rtools

![rtools-download](rtools-download.png)

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# What is Rtools

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# What is Rtools

Rtools is the official R for Windows toolchain bundle with:

- Mingw-w64 toolchains with `gcc 4.9.3` targeting both 32 and 64 bit
- Build utilities: `make`, `bash`, `tar`, etc
- Stuff for building base R: `TexInfo`, `TclTk`, `ICU`
 
--

You need Rtools to build:

- Base R

- R packages with C/C++/Fortran code

- __External libraries used by R and packages__

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# On System Dependencies

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# The rwinlib Organization

![rwinlib](rwinlib.png)

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# The rwinlib Organization

Manually maintaining the rwinlib builds is currently a lot of work.

Currently package authors need to manually download these libs during build.

For the new Rtools we want to:

- Take advantage of existing building and packaging tools from msys2
 - Automate the build and release process for libraries
 - Community maintained packaging scripts 
 
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# PART II: Rtools 4.0

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# Using Rtools 4.0

A beta version of rtools 4.0 and a version of R that has been configured for rtools40 is available from CRAN:

[![rtoolscran](rtoolscran.png)](https://cloud.r-project.org/bin/windows/testing/rtools40.html)

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# Using Rtools 4.0

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# Using Rtools 4.0

<br />

![rtools40](rtools40.png)

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# What's included?

Rtools 4.0 is a full unix-like environment based on msys2 (cygwin):

--
 - terminal: (mintty)

- shell (bash)

- make, sed, perl, etc

- mingw-w64 compilers targeting i686 and x86_84
 
--

- __a package manager to build and install anything else: pacman__

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# Using Pacman

Pacman is a port of the arch package manager. Some examples:

```r
# Sync repository index
pacman -Sy

# Upgrade installed packages
pacman -Su
```

To install new packages (for example libxml2)

```r
# Install both 32 and 64 bit build of libxm2
pacman -S mingw-w64-{i686,x86_64}-libxml2
```

More examples: https://cloud.r-project.org/bin/windows/testing/rtools40.html

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# Installing Libraries with Pacman

<video id="rtoolsvideo" class="fullscreenvideo" controls>
  <source src="rtools-fast.mp4" type="video/mp4">
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</video>

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# Pacman Package Formulas for Rtools 4.0

![rtools-packages](rtools-packages.png)

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# Rtools 4.0 Package Format

![arrow-pkgbuild](arrow-pkgbuild.png)

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# Building a Package in Rtools 4.0

<video id="rtoolscmake" class="fullscreenvideo" controls>
  <source src="cmake-fast.mp4" type="video/mp4">
Your browser does not support the video tag.
</video>

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# Automatic Building on AppVeyor

![appveyor-status](appveyor-status.png)

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# Automatic Building on AppVeyor

![rtoolsav](rtoolsav.png)

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# Automatic Deployment to Bintray

![appveyor-log](appveyor-log.png)

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# The Rtools 4.0 Binary Repository

![appveyor-deploy](appveyor-deploy.png)

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# Package is now live!

Now in Rtools 4.0 when users do:

```r
pacman -Syu
```

It will automatically update to the new Rtools 4.0 build.

RTools will automaticaly find the new libraries when building R package. No need to manually download and copy system libs and pass special compiler / linker flags.

Should feel much more like `apt` / `yum` / `brew`, where external libraries needed for building R packages can be installed from the command line, and it just works.

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# Recap

In Summary:

- Rtools as proper __build__ environment and package manager for __external libs__.

- Pacman allows for __packaging, distributing and installing__ libs, same as Linux, Homebrew.

- R automatically finds installed libs. No manual downloading / settings headers/libs.

- __Transparent and reproducible__ builds, __automated__ via CI, collaborative maintenance.

Hopefully, this will allow us to provide reliable, up-to-date libs for R on Windows.

These slides: `https://jeroen.github.io/rstudio2019`