update install procedure with troubleshooting from dev training sessi…

…on crash test

docs/source/installation.md

@@ -30,7 +30,8 @@ python version 3.9.x
 
 git
 
-During this installation, you can change the `python` command and replace it by the full path to the correct python executable (3.9.x)
+Note: if you have a more recent version of python installed, the `python` command is probably bound to it, resulting in a version issue with the installation scripts. If you installed python 3.9 on top, then you need to use the command `python3.9` hereafter.
+Make sure the requirements are properly installed with `python3.9 -m pip install mysql mysql-connector-python`. If the issue persists, you can replace the `python3.9` command by the full path to the correct python executable (3.9.x) in your filesystem.
 
 #### 2.2.2 Linux Installation
 
@@ -62,6 +63,10 @@ git clone https://github.com/os-climate/sostrades-dev-tools
 
 cd sostrades-dev-tools
 ```
+
+Important: the root directory name should not contain spaces, and it should be stored in a location where the scripts can write new files (beware of installation in remote filesystems). 
+If these conditions are not met, the `PrepareVenv` script might fail and a custom installation of the SoSTrades requirements might be necessary. Try installing in a local filesystem location without spaces.
+
 2. If needed configure model repositories : edit the `model_repositories.json` and `platform_repositories.json` according to what repositories you want. The provided `model_repositories.json` file includes the WITNESS model repositories, as well as the optimization plugins repository required to run WITNESS optimizations :
 
 ```json
@@ -309,11 +314,13 @@ If you never installed any MySQL products you will get this screen. Click on Add
 
 ![](images/Mysql_add.png)
 
-If you can not find MySQL 5.7, click on "Edit" and change the filter of "Maturity" field to "Other Releases".
+If you cannot find MySQL 5.7, click on "Edit" and change the filter of "Maturity" field to "Other Releases".
 
 ![](images/Mysql_filter.png)
 ![](images/Mysql_5.7.png)
 
+If you cannot find MySQL 5.7 among the options yet, then you must download the [version-specific installer](https://dev.mysql.com/get/Downloads/MySQLInstaller/mysql-installer-community-5.7.44.0.msi) and repeat the steps above.
+
 Once the MySQL Server is selected click on Next then execute on the next screen. Let everything by default until to get the screen asking you to enter the password. Enter you password twice and click next to complete all the installation of MySQL.
 
 ![](images/Mysql_credential.png)
@@ -355,6 +362,7 @@ To create an user to access to SoSTrades platform run `CreateUser.py`:
 ```
 python scripts\CreateUser.py
 ```
+Important: the `CreateUser.py` script will ask you to input some information (user, name, last name and e-mail). Leaving any of these fields empty will result in the script crashing, at least a character is required. 
 
 If you want to update Ontology execute the script `UpdateOntology.py`. This script could take more than 15mn it depends on the number of repository you have.