update readme and fix

Author: dakk

README.md

@@ -43,7 +43,7 @@ GWeatherRouting is an opensource sailing route calculator written in python and:
 
 ## Installation
 
-1. Make sure to have Python >= 3.9 installed and the `pip` package manager.
+1. Make sure to have Python >= 3.8 installed and the `pip` package manager.
 2. Install the following dependencies using your OS package manager (e.g: debian=apt, macos=homebrew) Be aware that some packages have different names with different package managers.
    - gobject-introspection
    - gdal
@@ -56,6 +56,16 @@ GWeatherRouting is an opensource sailing route calculator written in python and:
    - pkg-config
    - eccodes
 
+> [!NOTE]
+> Ubuntu uses an old version of GDAL and other libraries; in order to use a never version, use the following commands:
+> ```
+>       sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable
+>       sudo apt-get update
+>       sudo apt-get install gdal-bin libgdal-dev
+>       sudo apt-get install libgtk-4-dev libgtk-4-1
+>       pip install git+https://github.com/vext-python/vext@32ad4d1c5f45797e244df1d2816f76b60f28e20e
+> ```
+
 > [!NOTE]  
 > If you are using a `virtualenv` you need to make symbolic links from the UI libraries to your `venv` folder (this is not needed using system interpreter outside venv).
 

setup.py

@@ -26,7 +26,7 @@
     buildOptions = {"build_exe": {"packages": ["gi"], "include_files": []}}
     executables = [Executable("main.py")]  #  icon="evm_bg_KYa_icon.ico")
 
-GDAL_VERSION = subprocess.check_output(['gdal-config', '--version'], shell=True).decode('ascii').strip()
+GDAL_VERSION = subprocess.check_output(['gdal-config', '--version']).decode('ascii').strip()
 
 requirements = open("requirements.txt", "r").read().split("\n")[:-1]
 requirements.append(f'GDAL=={GDAL_VERSION}')