updated instructions

README.md

@@ -1,16 +1,28 @@
 # ros_from_src
 
-Build ros from source without using a PPA in a dockerfile (and later a github action).
-Probably just copy what archlinux is doing.
+Build ros from source without using a PPA (or even the debian ros packages):
 
     git clone [email protected]:lucasw/ros_from_src.git
-    cd ros_from_src
-    docker build .
+    mkdir build
+    cd build
+    ROSCONSOLE=https://github.com/ros/rosconsole ../ros_from_src/git_clone.sh
+    # (take look at this script before running as sudo)
+    sudo ../ros_from_src/dependencies.sh
+    ../ros_from_src/build.sh
 
-To build with another ubuntu version:
+The above should be similar to what is in the github action: .github/workflows/ubuntu_20_04.yaml
 
-    docker build --build-arg IMAGE=ubuntu:21.10 --build-arg PYTHON_MINOR_VERSION=9 . -t ros2110
+    export ROS_BUILD_DIR=$HOME/own/build/ros_from_src  # or whatever
+    export CMAKE_PREFIX_PATH=$CMAKE_PREFIX_PATH:$ROS_BUILD_DIR/ros/lib/cmake
+    # make this python3.8 if python --version shows that to be your version
+    export PYTHONPATH=$PYTHONPATH:$ROS_BUILD_DIR/ros/lib/python3.9/site-packages/
+    # source $ROS_BUILD_DIR/ros/setup.bash
+    source $ROS_BUILD_DIR/catkin_ws/devel/setup.bash
 
-Build with default version, but give it a tag:
+To build with docker and another ubuntu version:
 
-    docker build --build-arg IMAGE=ubuntu:20.04 . -t ros2004
+    docker build --build-arg IMAGE=ubuntu:21.10 --build-arg ROSCONSOLE=https://github.com/ros/rosconsole --build-arg PYTHON_MINOR_VERSION=9 . -t ros2110
+
+Build with default Ubuntu 22.04 version:
+
+    docker build . -t ros2204