MSYS2 : Remove setup of PATH env var in install_dependencies (#6349)

Fix #5740 : It's better not to modify user environment without him knowing. Moreover, setting PATH is optional. So move instructions to documentation

Fix #6211 : documentation typo

CHANGELOG.md

@@ -10,6 +10,10 @@ PLATFORM/IDE SPECIFIC
 ### makefiles
 - makefiles: addon data not being copied(#2903).
 
+### msys2
+- setup : removed automatic setup of PATH environment variable(#5740). Move instructions to setup PATY to documentation.
+- documentation : fix typo (#6211) and insist on the use of MINGW32 shell. 
+
 ADDONS
 ------
 ### ofxOpenCv

docs/msys2.md

@@ -1,43 +1,122 @@
 [openFrameworks](http://openframeworks.cc/) | [Documentation table of contents](table_of_contents.md)
 
+
 MSYS2
 =====
 
-Installing MSYS2 
+Installing msys2
 ----------------
 
-First, install MSYS2 using the [one-click installer](https://msys2.github.io/) or 
+First, install MSYS2 using the [one-click installer](https://msys2.github.io/) or
 directly unzipping the archive from their [repository](http://sourceforge.net/projects/msys2/files/Base/x86_64/)
 
+If you have an old install of MSYS2 (before 2018), it's recommended to do a fresh install.
+
 If you are going to use QtCreator you should install msys2 in the default install folder, c:\msys64
 
-Open a MSYS2 shell and update the system packages :
 
-    pacman --noconfirm  --needed -Sy bash pacman pacman-mirrors msys2-runtime
-
-Close the shell and open a new one to update the remaining packages :
 
-    pacman --noconfirm -Su
+Now, let's update the MSYS2 installation.
+From an MSYS2 shell (it can be MSYS, MINGW32 or MINGW64), run :
+
+```sh
+pacman -Syu --noconfirm --needed
+```
 
-You are now ready to install openFrameworks.	
+If some system files are updated, you may be requested to close the shell.
+If that happens, close the shell as instructed and open a new one to update the remaining packages using the same command :
+
+```sh
+pacman -Syu --noconfirm --needed
+```
+
+You are now ready to install openFrameworks.
 
 
 Installing openFrameworks
 -------------------------
 
-Download and unzip the msys2 version of oF.
+**IMPORTANT**
+MSYS2 comes in 3 flavors : MSYS (msys2.exe), MINGW32 (mingw32.exe), MINGW64 (mingw64.exe).
+This really important to remember as many problems with running OF with MSYS2 come from using the wrong flavor.
+As of today, only **MINGW32** is supported.
+So you must use the mingw32.exe shell to run oF.
 
-Open an MSYS shell and install OF dependencies:
+For the following instructions, it assumed that MSYS2 is installed in `C:\msys64`.
+If it has been installed elsewhere, adapt the instructions to reflect your MSYS2 installation path
 
-    cd your_oF_directory/scripts/msys2
-    ./install_dependencies.sh
-	
-Open an **MINGW32** shell and compile oF libraries:
+Download and unzip the **qt creator / msys2** version of oF. 
+**DO NOT INSTALL** oF in a folder having space or other special character.
+
+Open an **MINGW32** shell (`C:\msys64\mingw32.exe` ) and install OF dependencies:
 
-	cd your_oF_directory/libs/openFrameworksCompiled/project
+```sh
+cd your_oF_directory/scripts/msys2
+./install_dependencies.sh
+```
+
+Open an **MINGW32** shell (run `C:\msys64\mingw32.exe`) and compile oF libraries:
+
+    cd your_oF_directory/libs/openFrameworksCompiled/project
     make
 
-You can speed-up compilation using parallel build `make -j${NUMBER_OF_PROCESSORS}`
+You can speed-up compilation using parallel build `make -j4` or the number of cores you want it to use
+
+
+Setting the PATH variable
+-------------------------
+
+Setting the PATH variable is an optional step but is also the cause of many trouble.
+
+As of v0.10.1, the install_dependencies.sh script does it in an wrong way!
+
+### Why would you need to set the PATH variable ?
+
+__To be able to run my oF application by double clicking on it.__
+
+To run, the application needs to have the dll it was compiled with.
+If the required dll is not found at the location of your application, Windows will traverse the folders in your PATH to find it.
+If `C:\msys64\mingw32\bin` is included in your PATH, it will hopefully find the right dll.
+However, it may find a dll with a matching name in a different folder that is not compatible...  
+It may also happen that, after an MSYS2 update, it finds a newer version in `C:\msys64\mingw32\bin` that is also incompatible...
+
+The solution is to copy all the needed dlls in the application folder.
+This can be easily done with the command : 
+
+```sh
+make copy_dlls
+```
+This will also ease the installation of the application on a different computer....
+
+
+__To compile oF in IDE (Qt Creator or VS Code )__
+
+These softwares will try to detect compiler programs (gcc, make) by scanning the PATH variable.
+So it's an easy way to setup up your IDE.
+There may also be some settings in the IDE to configure where to find the programs.
+That gives you better control.
+As in the previous point, relying on the PATH variable to find the programs may result in unexpected behaviours (for example, using Windows C:\Windows\System32\find.exe instead of MSYS2 C:\msys64\usr\bin\find.exe)
+
+It may be interesting to write a wrapper batch file to lauch your IDE where you set the PATH to use.
+This way you do not pollute your PATH system-wide.
+
+### I've decided to use the PATH variable. How do I set it ?
+
+You can find how to set the PATH in windows here: http://www.computerhope.com/issues/ch000549.htm
+
+You'll need to add `c:\msys64\mingw32\bin` and `c:\msys64\usr\bin` to your PATH in **that order**.
+There are two ways:
+
+1. Either add them via 'Environment Variables' from the Control Panel > System > Advanced System Settings.
+2. Or you can also set the PATH from the command line: open a Windows cmd prompt and set you user PATH.
+```
+setx PATH "c:\msys64\mingw32\bin;c:\msys64\usr\bin;%PATH%"
+```
+
+Don't forget to logoff/logon as PATH is updated at logon.
+
+That's all, now go to the your_oF_directory/examples folder, where you will find
+the examples, and have fun!
 
 
 Running examples
@@ -47,21 +126,23 @@ Compile the example (for example the 3DPrimitivesExample)
     cd your_oF_directory/examples/3d/3DPrimitivesExample
     make
 
-At this point, `make run` or  double-click on the exe file to launch. 
+At this point, `make run` to launch. 
 
+To be able to double-click on the exe file to run it, run `make copy_dlls` (if you haven't set the PATH!)
 
 Makefile
 --------
 
 Every example has a Makefile you can configure using the files config.make
 and addons.make.
 
-config.make: This file has options to add search paths, libraries, etc., the 
+config.make: This file has options to add search paths, libraries, etc., the
 syntax is the usual syntax in makefiles, there's help comments inside the file.
 
-addons.make: if you want to use an addon which is inside the addons folder, just 
+addons.make: if you want to use an addon which is inside the addons folder, just
 add its name in a new line in this file.
 
+
 Dlls
 ----
 
@@ -73,6 +154,7 @@ from the msys2 terminal and it'll copy the necesary dlls to the project bin fold
 
 This is still experimental so if you find any problem please [report it on github](https://github.com/openframeworks/openFrameworks/new?title=Problem%20with%20msys2%20dlls)
 
+
 QtCreator
 ---------
 

scripts/msys2/install_dependencies.sh

@@ -29,14 +29,6 @@ while [[ $# > 0 ]] ; do
 	exit 1
 done
 
-NOT_HAS_PATH=$(cmd /c "echo %PATH%" | grep mingw32\\bin > /dev/null; echo $?)
-if [ "$NOT_HAS_PATH" -ne "0" ]; then
-	cd /
-	MSYS2_ROOT=$(pwd)
-	MSYS2_ROOT=$(cygpath -w $MSYS2_ROOT)
-	setx PATH "%PATH%;${MSYS2_ROOT}mingw32\\bin;${MSYS2_ROOT}usr\\bin\\"
-	echo "set path to ${MSYS2_ROOT}mingw32\\bin;${MSYS2_ROOT}usr\\bin\\"
-fi
 
 #Install packages
 if [ -z ${confirm+x} ]; then