Remove $CONDA_PREFIX/bin from PATH when testing installation on UNIX …

…/ Conda

Also remove all *CONDA* environment variables, so as to match
"Conda-based" environments as much as possible.

A "Conda-based" environment is a Conda environment whose packages are
launched outside of the environment, as e.g. when using the Khiops Python
library from a JuPyter notebook which:
- is installed outside the Conda environment where Khiops is installed
- uses a Python kernel (via the `ipykernel` Conda package) which is
  installed inside the Conda envirovnment.

This configuration results in two particularities:
- `sys.path` is correctly set according to the Conda environment (as
  the Python kernel is installed therein)
- `PATH` and the operating system environment (except for Python
  aspects) does not take this Conda environment into account:
  - `*CONDA*` variables are not set (most notably, `CONDA_PREFIX` is not
    set)
  - `$CONDA_PREFIX/bin` is not in the `PATH`.

.github/actions/test-khiops-install/action.yml

@@ -5,6 +5,11 @@ runs:
   using: composite
   steps:
     - name: Test that the executables are installed (Linux/macOS)
+      # We store path to khiops_env
+      # We remove $CONDA_PREFIX/bin from PATH (with effect only in Conda
+      # environments)
+      # We unset all *CONDA* variables (to test correct functioning of
+      # khiops_env in Conda-based environments)
       # We call khiops_env a first time to test the calling of _khiopsgetprocnumber
       # then we play with KHIOPS_PROC_NUMBER:
       # - with KHIOPS_PROC_NUMBER=2, khiops should not use MPI, we check that KHIOPS_MPI_COMMAND is empty
@@ -19,13 +24,37 @@ runs:
         OMPI_MCA_rmaps_base_oversubscribe: true
         KHIOPS_MPI_VERBOSE: true
       run: |
+        # Set khiops_env directory
+        KHIOPS_ENV_DIR=$(dirname $(type -P khiops_env))
+
+        # If CONDA_PREFIX is defined, then remove $CONDA_PREFIX/bin from the
+        # PATH and unset all *CONDA* environment variables
+        if [[ -n ${{ env.CONDA_PREFIX }} ]]
+        then
+          echo
+          echo --- CONDA_PREFIX is set to $CONDA_PREFIX
+
+          # Remove $CONDA_PREFIX/bin from the PATH
+          export PATH=$(echo $PATH | sed "s#$CONDA_PREFIX/bin:##g")
+
+          # Unset *CONDA* environment variables
+          # As a corrolary, CONDA_PREFIX is unset
+          # Note: There is no way to remove these variables from GITHUB_ENV
+          # (see https://github.com/actions/runner/issues/1126)
+          for CONDA_VAR in $(env | grep CONDA)
+          do
+            unset $(echo $CONDA_VAR | cut -d '=' -f 1)
+          done
+        fi
         echo
         echo --- Khiops environment with KHIOPS_PROC_NUMBER not set
-        khiops_env --env
+
+        # khiops_env is not in the path anymore, for Conda environments
+        $KHIOPS_ENV_DIR/khiops_env --env
         echo
         export KHIOPS_PROC_NUMBER=2
         echo --- Khiops environment with KHIOPS_PROC_NUMBER=$KHIOPS_PROC_NUMBER
-        source khiops_env --env
+        source $KHIOPS_ENV_DIR/khiops_env --env
         if [ ! -z "$KHIOPS_MPI_COMMAND" ]; 
         then 
           echo "::error::MPI is used even though there are only 2 procs available"
@@ -34,7 +63,7 @@ runs:
         echo
         export KHIOPS_PROC_NUMBER=8
         echo --- Khiops environment with KHIOPS_PROC_NUMBER=$KHIOPS_PROC_NUMBER
-        source khiops_env --env
+        source $KHIOPS_ENV_DIR/khiops_env --env
         if [ ! -z "$KHIOPS_MPI_ERROR" ]; 
         then 
           echo "::error::Unexpected MPI error: $KHIOPS_MPI_ERROR"
@@ -47,10 +76,10 @@ runs:
         fi
         echo
         echo --- Khiops status
-        khiops -s
+        $KHIOPS_ENV_DIR/khiops -s
         echo
         echo --- Khiops Coclustering status
-        khiops_coclustering -s
+        $KHIOPS_ENV_DIR/khiops_coclustering -s
     - name: Test that the executables are installed (windows)
       if: runner.os == 'Windows'
       shell: cmd /C call {0}