Fix: handle exception in get_link_names for single-link group

src/compas_fab/robots/newenv/Scripts/activate

@@ -0,0 +1,70 @@
+# This file must be used with "source bin/activate" *from bash*
+# You cannot run it directly
+
+deactivate () {
+    # reset old environment variables
+    if [ -n "${_OLD_VIRTUAL_PATH:-}" ] ; then
+        PATH="${_OLD_VIRTUAL_PATH:-}"
+        export PATH
+        unset _OLD_VIRTUAL_PATH
+    fi
+    if [ -n "${_OLD_VIRTUAL_PYTHONHOME:-}" ] ; then
+        PYTHONHOME="${_OLD_VIRTUAL_PYTHONHOME:-}"
+        export PYTHONHOME
+        unset _OLD_VIRTUAL_PYTHONHOME
+    fi
+
+    # Call hash to forget past commands. Without forgetting
+    # past commands the $PATH changes we made may not be respected
+    hash -r 2> /dev/null
+
+    if [ -n "${_OLD_VIRTUAL_PS1:-}" ] ; then
+        PS1="${_OLD_VIRTUAL_PS1:-}"
+        export PS1
+        unset _OLD_VIRTUAL_PS1
+    fi
+
+    unset VIRTUAL_ENV
+    unset VIRTUAL_ENV_PROMPT
+    if [ ! "${1:-}" = "nondestructive" ] ; then
+    # Self destruct!
+        unset -f deactivate
+    fi
+}
+
+# unset irrelevant variables
+deactivate nondestructive
+
+# on Windows, a path can contain colons and backslashes and has to be converted:
+if [ "${OSTYPE:-}" = "cygwin" ] || [ "${OSTYPE:-}" = "msys" ] ; then
+    # transform D:\path\to\venv to /d/path/to/venv on MSYS
+    # and to /cygdrive/d/path/to/venv on Cygwin
+    export VIRTUAL_ENV=$(cygpath "D:\LOCAL-CODE COPY\compas_fab\src\compas_fab\robots\newenv")
+else
+    # use the path as-is
+    export VIRTUAL_ENV="D:\LOCAL-CODE COPY\compas_fab\src\compas_fab\robots\newenv"
+fi
+
+_OLD_VIRTUAL_PATH="$PATH"
+PATH="$VIRTUAL_ENV/Scripts:$PATH"
+export PATH
+
+# unset PYTHONHOME if set
+# this will fail if PYTHONHOME is set to the empty string (which is bad anyway)
+# could use `if (set -u; : $PYTHONHOME) ;` in bash
+if [ -n "${PYTHONHOME:-}" ] ; then
+    _OLD_VIRTUAL_PYTHONHOME="${PYTHONHOME:-}"
+    unset PYTHONHOME
+fi
+
+if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT:-}" ] ; then
+    _OLD_VIRTUAL_PS1="${PS1:-}"
+    PS1="(newenv) ${PS1:-}"
+    export PS1
+    VIRTUAL_ENV_PROMPT="(newenv) "
+    export VIRTUAL_ENV_PROMPT
+fi
+
+# Call hash to forget past commands. Without forgetting
+# past commands the $PATH changes we made may not be respected
+hash -r 2> /dev/null

src/compas_fab/robots/newenv/Scripts/activate.bat

@@ -0,0 +1,34 @@
+@echo off
+
+rem This file is UTF-8 encoded, so we need to update the current code page while executing it
+for /f "tokens=2 delims=:." %%a in ('"%SystemRoot%\System32\chcp.com"') do (
+    set _OLD_CODEPAGE=%%a
+)
+if defined _OLD_CODEPAGE (
+    "%SystemRoot%\System32\chcp.com" 65001 > nul
+)
+
+set VIRTUAL_ENV=D:\LOCAL-CODE COPY\compas_fab\src\compas_fab\robots\newenv
+
+if not defined PROMPT set PROMPT=$P$G
+
+if defined _OLD_VIRTUAL_PROMPT set PROMPT=%_OLD_VIRTUAL_PROMPT%
+if defined _OLD_VIRTUAL_PYTHONHOME set PYTHONHOME=%_OLD_VIRTUAL_PYTHONHOME%
+
+set _OLD_VIRTUAL_PROMPT=%PROMPT%
+set PROMPT=(newenv) %PROMPT%
+
+if defined PYTHONHOME set _OLD_VIRTUAL_PYTHONHOME=%PYTHONHOME%
+set PYTHONHOME=
+
+if defined _OLD_VIRTUAL_PATH set PATH=%_OLD_VIRTUAL_PATH%
+if not defined _OLD_VIRTUAL_PATH set _OLD_VIRTUAL_PATH=%PATH%
+
+set PATH=%VIRTUAL_ENV%\Scripts;%PATH%
+set VIRTUAL_ENV_PROMPT=(newenv) 
+
+:END
+if defined _OLD_CODEPAGE (
+    "%SystemRoot%\System32\chcp.com" %_OLD_CODEPAGE% > nul
+    set _OLD_CODEPAGE=
+)

src/compas_fab/robots/newenv/Scripts/deactivate.bat

@@ -0,0 +1,22 @@
+@echo off
+
+if defined _OLD_VIRTUAL_PROMPT (
+    set "PROMPT=%_OLD_VIRTUAL_PROMPT%"
+)
+set _OLD_VIRTUAL_PROMPT=
+
+if defined _OLD_VIRTUAL_PYTHONHOME (
+    set "PYTHONHOME=%_OLD_VIRTUAL_PYTHONHOME%"
+    set _OLD_VIRTUAL_PYTHONHOME=
+)
+
+if defined _OLD_VIRTUAL_PATH (
+    set "PATH=%_OLD_VIRTUAL_PATH%"
+)
+
+set _OLD_VIRTUAL_PATH=
+
+set VIRTUAL_ENV=
+set VIRTUAL_ENV_PROMPT=
+
+:END

src/compas_fab/robots/newenv/pyvenv.cfg

@@ -0,0 +1,5 @@
+home = C:\Program Files\Python312
+include-system-site-packages = false
+version = 3.12.4
+executable = D:\myenv\myenv\Scripts\python.exe
+command = D:\myenv\myenv\Scripts\python.exe -m venv D:\LOCAL-CODE COPY\compas_fab\src\compas_fab\robots\newenv

src/compas_fab/robots/robot.py

@@ -387,8 +387,14 @@ def get_link_names(self, group=None):
         base_link_name = self.get_base_link_name(group)
         end_effector_link_name = self.get_end_effector_link_name(group)
         link_names = []
-        for link in self.model.iter_link_chain(base_link_name, end_effector_link_name):
-            link_names.append(link.name)
+        if not base_link_name or not end_effector_link_name:
+            raise ValueError("Invalid base or end effector link name for the specified group.")
+        try:
+            for link in self.model.iter_link_chain(base_link_name, end_effector_link_name):
+                link_names.append(link.name)
+        except Exception as e:
+            raise Exception(f"No chain found between the specified elements: {str(e)}")
+
         return link_names
 
     def get_link_names_with_collision_geometry(self):

src/compas_fab/robots/test_robot.py

@@ -0,0 +1,18 @@
+# Import necessary modules
+try:
+    from compas_fab.robots.ur5 import Robot  # Attempt to import the UR5 robot directly
+    robot = Robot()  # Instantiate the UR5 robot
+except ImportError:  # Catch the specific ImportError
+    from compas_fab.robots import RobotLibrary  # Fall back to RobotLibrary
+    robot = RobotLibrary.ur5()  # Instantiate the UR5 robot from the library
+
+# Check if robot has been initialized successfully
+if robot:
+    # List all group names in the robot model
+    print("Available Groups:", robot.group_names)  # Print available group names
+else:
+    print("Failed to initialize the robot.")
+
+if __name__ == "__main__":
+    # Place the script's main code here if needed
+    pass  # Placeholder for any additional code