Fix gnuplot detection

aidge_core/mem_info.py

 import os
+import subprocess
 import shutil
 from pathlib import Path
 import aidge_core
@@ -41,6 +42,18 @@ def compute_default_mem_info(scheduler: aidge_core.Scheduler) -> Tuple[int, List
     return mem_size, mem_info
 
 
+def _gnuplot_installed():
+    try:
+        # Run gnuplot with the --version flag and capture the output
+        subprocess.run(["gnuplot", "--version"])
+        return True
+    except FileNotFoundError:
+        aidge_core.Log.warn("Gnuplot is not installed.")
+        return False
+    except subprocess.CalledProcessError:
+        aidge_core.Log.warn("Gnuplot command found but failed to run.")
+        return False
+
 def generate_optimized_memory_info(scheduler: aidge_core.Scheduler, stats_folder: Path = None, wrapping: bool = False) -> Tuple[int, List[dict]]:
     """Generates optimized memory information for a computation graph managed by a scheduler.
 
@@ -73,21 +86,20 @@ def generate_optimized_memory_info(scheduler: aidge_core.Scheduler, stats_folder
 
     # List of nodes which are connected at the input of the graph (None if input is not connected)
     nodes_at_input = [n[0] for n in scheduler.graph_view().inputs()]
-    # Return 0 ==> gnuplot installed
-    if os.system("gnuplot --version > /dev/null 2>&1") == 0:
-        # Use gnuplot to generate the log
-        if isinstance(stats_folder, str):
-            stats_folder = Path(stats_folder)
-        os.makedirs(str(Path(stats_folder) / "graph"), exist_ok=True)
-        mem_manager.log("memory_info")
-        os.chmod("memory_info_plot.gnu", 0o777)
-        os.system("./memory_info_plot.gnu")
-        shutil.move("memory_info", str(Path(stats_folder) / "graph" / "memory_info"))
-        shutil.move("memory_info_plot.png", str(
-            Path(stats_folder) / "graph" / "memory_info_plot.png"))
-        os.remove("memory_info_plot.gnu")
-    elif stats_folder is not None:
-        aidge_core.Log.warn("Warning: gnuplot is not installed, could not generate stat folder.")
+
+    if stats_folder is not None:
+        if _gnuplot_installed():
+            # Use gnuplot to generate the log
+            os.makedirs(str(Path(stats_folder) / "graph"), exist_ok=True)
+            mem_manager.log("memory_info")
+            os.chmod("memory_info_plot.gnu", 0o777)
+            os.system("./memory_info_plot.gnu")
+            shutil.move("memory_info", str(Path(stats_folder) / "graph" / "memory_info"))
+            shutil.move("memory_info_plot.png", str(
+                Path(stats_folder) / "graph" / "memory_info_plot.png"))
+            os.remove("memory_info_plot.gnu")
+        else:
+            aidge_core.Log.warn("Warning: gnuplot is not installed, could not generate stat folder.")
     # In the export, we currently use an unified memory buffer whose size
     # is determined by the memory peak usage
     mem_size = mem_manager.get_peak_usage()