diff --git a/.cirrus.yml b/.cirrus.yml
index db1b71e2f..fc68ca1b0 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -16,8 +16,8 @@ task:
 
   script:
     - brew install libomp
-    - brew install python@3.12
-    - $(brew --prefix python@3.12)/bin/python3.12 -m venv .test_venv
+    - brew install python@3.11
+    - $(brew --prefix python@3.11)/bin/python3.11 -m venv .test_venv
     - source .test_venv/bin/activate
     - pip install --upgrade pip
     - sh ./pytest.sh
diff --git a/keopscore/keopscore/config/base_config.py b/keopscore/keopscore/config/base_config.py
index fdabf91ba..3519bc5d2 100644
--- a/keopscore/keopscore/config/base_config.py
+++ b/keopscore/keopscore/config/base_config.py
@@ -5,7 +5,7 @@
 import shutil
 from pathlib import Path
 import keopscore
-from keopscore.utils.misc_utils import KeOps_Warning, KeOps_OS_Run
+from keopscore.utils.misc_utils import KeOps_Warning, KeOps_OS_Run, get_brew_prefix
 from keopscore.utils.misc_utils import CHECK_MARK, CROSS_MARK
 
 
@@ -219,48 +219,13 @@ def print_compile_options(self):
         """Print the compile options."""
         print(f"Compile Options: {self.compile_options}")
 
-    def get_brew_prefix(self):
-        """Get Homebrew prefix path using KeOps_OS_Run"""
-        if platform.system() != "Darwin":
-            return None
-
-        # Redirect brew --prefix to a temporary file
-        tmp_file = "/tmp/brew_prefix.txt"
-
-        # brew --prefix > /tmp/brew_prefix.txt
-        # We use shell redirection so the output ends up in the file
-        KeOps_OS_Run(f"brew --prefix > {tmp_file}")
-
-        # Now read the file if it was created
-        if os.path.exists(tmp_file):
-            with open(tmp_file, "r") as f:
-                prefix = f.read().strip()
-
-            # Optional: Clean up
-            os.remove(tmp_file)
-
-            # Return the prefix if it's non-empty
-            return prefix if prefix else None
-
-        # If file doesn't exist or is empty, return None
-        return None
-
     def get_use_Apple_clang(self):
         """Detect if using Apple Clang."""
         is_apple_clang = False
         if platform.system() == "Darwin":
-            tmp_file = "/tmp/compiler_version.txt"
-            # Run "c++ --version" and write output to /tmp/compiler_version.txt
-            KeOps_OS_Run(f"c++ --version > {tmp_file}")
-
-            # Now read the file
-            if os.path.exists(tmp_file):
-                with open(tmp_file, "r") as f:
-                    compiler_info = f.read()
-                os.remove(tmp_file)
-
-                # Check if 'Apple clang' appears in the output
-                is_apple_clang = "Apple clang" in compiler_info
+            compiler_info = KeOps_OS_Run(f"c++ --version").stdout.decode("utf-8")
+            # Check if 'Apple clang' appears in the output
+            is_apple_clang = "Apple clang" in compiler_info
         return is_apple_clang
 
     def set_cpp_flags(self):
@@ -272,10 +237,11 @@ def set_cpp_flags(self):
         # Add OpenMP flags based on compiler
         if self.get_use_Apple_clang():
             # For Apple Clang, you need to specify OpenMP library location
-            brew_prefix = self.get_brew_prefix()
-            self.cpp_flags += f" -Xpreprocessor -fopenmp"
-            self.cpp_flags += f" -I{brew_prefix}/opt/libomp/include"
-            self.cpp_flags += f" -L{brew_prefix}/opt/libomp/lib"
+            brew_prefix = get_brew_prefix()
+            if brew_prefix is not None:
+                self.cpp_flags += f" -Xpreprocessor -fopenmp"
+                self.cpp_flags += f" -I{brew_prefix}/opt/libomp/include"
+                self.cpp_flags += f" -L{brew_prefix}/opt/libomp/lib"
         else:
             # For GCC and other compilers
             self.cpp_flags += " -fopenmp"
diff --git a/keopscore/keopscore/config/cuda.py b/keopscore/keopscore/config/cuda.py
index a52e2b5b1..320f700e9 100644
--- a/keopscore/keopscore/config/cuda.py
+++ b/keopscore/keopscore/config/cuda.py
@@ -16,13 +16,12 @@
 import shutil
 from os.path import join
 import platform
-import tempfile
 import subprocess
 import sys
 import keopscore
 from keopscore.utils.misc_utils import KeOps_Warning
 from keopscore.utils.misc_utils import KeOps_OS_Run
-from keopscore.utils.misc_utils import CHECK_MARK, CROSS_MARK
+from keopscore.utils.misc_utils import CHECK_MARK, CROSS_MARK, get_include_file_abspath
 
 
 class CUDAConfig:
@@ -341,17 +340,7 @@ def get_cuda_include_path(self):
         return self.cuda_include_path
 
     def get_include_file_abspath(self, filename):
-        tmp_file = tempfile.NamedTemporaryFile(dir=self.get_build_folder()).name
-        KeOps_OS_Run(
-            f'echo "#include <{filename}>" | {self.cxx_compiler} -M -E -x c++ - | head -n 2 > {tmp_file}'
-        )
-        strings = open(tmp_file).read().split()
-        abspath = None
-        for s in strings:
-            if filename in s:
-                abspath = s
-        os.remove(tmp_file)
-        return abspath
+        return get_include_file_abspath(filename, self.cxx_compiler)
 
     def set_nvrtc_flags(self):
         """Set the NVRTC flags for CUDA compilation."""
diff --git a/keopscore/keopscore/config/openmp.py b/keopscore/keopscore/config/openmp.py
index 2e3cc61c9..66ab72317 100644
--- a/keopscore/keopscore/config/openmp.py
+++ b/keopscore/keopscore/config/openmp.py
@@ -5,8 +5,7 @@
 import platform
 from ctypes.util import find_library
 
-from keopscore.utils.misc_utils import KeOps_Warning
-from keopscore.utils.misc_utils import KeOps_OS_Run
+from keopscore.utils.misc_utils import KeOps_Warning, KeOps_OS_Run, get_brew_prefix
 from keopscore.utils.misc_utils import CHECK_MARK, CROSS_MARK
 
 
@@ -84,32 +83,6 @@ def check_compiler_for_openmp(self):
             os.remove(test_file)
             return False
 
-    def get_brew_prefix(self):
-        """Get Homebrew prefix path using KeOps_OS_Run"""
-        if platform.system() != "Darwin":
-            return None
-
-        # Redirect brew --prefix to a temporary file
-        tmp_file = "/tmp/brew_prefix.txt"
-
-        # brew --prefix > /tmp/brew_prefix.txt
-        # We use shell redirection so the output ends up in the file
-        KeOps_OS_Run(f"brew --prefix > {tmp_file}")
-
-        # Now read the file if it was created
-        if os.path.exists(tmp_file):
-            with open(tmp_file, "r") as f:
-                prefix = f.read().strip()
-
-            # Optional: Clean up
-            os.remove(tmp_file)
-
-            # Return the prefix if it's non-empty
-            return prefix if prefix else None
-
-        # If file doesn't exist or is empty, return None
-        return None
-
     def check_openmp_libraries(self):
         if self.os.startswith("Linux"):
             openmp_lib = find_library("gomp")
@@ -121,10 +94,13 @@ def check_openmp_libraries(self):
                 return True
         # Specific check for M1/M2/M3 apple Silicon chips
         elif self.os.startswith("Darwin") and platform.machine() in ["arm64", "arm64e"]:
-            brew_prefix = self.get_brew_prefix()
-            openmp_path = f"{brew_prefix}/opt/libomp/lib/libomp.dylib"
-            openmp_lib = openmp_path if os.path.exists(openmp_path) else None
-            if not openmp_lib:
+            brew_prefix = get_brew_prefix()
+            if brew_prefix is not None:
+                openmp_path = f"{brew_prefix}/opt/libomp/lib/libomp.dylib"
+                openmp_lib = openmp_path if os.path.exists(openmp_path) else None
+            else:
+                openmp_lib = None
+            if openmp_lib is None:
                 KeOps_Warning(
                     "OpenMP library not found, it must be downloaded through Homebrew for apple Silicon chips"
                 )
diff --git a/keopscore/keopscore/utils/gpu_utils.py b/keopscore/keopscore/utils/gpu_utils.py
index fef910b87..df5b1debc 100644
--- a/keopscore/keopscore/utils/gpu_utils.py
+++ b/keopscore/keopscore/utils/gpu_utils.py
@@ -1,6 +1,5 @@
 import ctypes
 from ctypes.util import find_library
-import tempfile
 
 
 from keopscore.utils.misc_utils import (
@@ -8,6 +7,7 @@
     KeOps_Warning,
     find_library_abspath,
     KeOps_OS_Run,
+    get_include_file_abspath,
 )
 
 import keopscore
@@ -81,7 +81,7 @@ def get_cuda_include_path():
 
     # last try, testing if by any chance the header is already in the default
     # include path of gcc
-    path_cudah = get_include_file_abspath("cuda.h")
+    path_cudah = get_include_file_abspath("cuda.h", config.cxx_compiler())
     if path_cudah:
         path = os.path.dirname(path_cudah)
     if os.path.isfile(join(path, "nvrtc.h")):
@@ -100,20 +100,6 @@ def get_cuda_include_path():
     )
 
 
-def get_include_file_abspath(filename):
-    tmp_file = tempfile.NamedTemporaryFile(dir=config.get_build_folder()).name
-    KeOps_OS_Run(
-        f'echo "#include <{filename}>" | {config.cxx_compiler()} -M -E -x c++ - | head -n 2 > {tmp_file}'
-    )
-    strings = open(tmp_file).read().split()
-    abspath = None
-    for s in strings:
-        if filename in s:
-            abspath = s
-    os.remove(tmp_file)
-    return abspath
-
-
 def orig_cuda_include_fp16_path():
     """
     We look for float 16 cuda headers cuda_fp16.h and cuda_fp16.hpp
diff --git a/keopscore/keopscore/utils/misc_utils.py b/keopscore/keopscore/utils/misc_utils.py
index f48b102c4..887127dba 100644
--- a/keopscore/keopscore/utils/misc_utils.py
+++ b/keopscore/keopscore/utils/misc_utils.py
@@ -5,6 +5,7 @@
 import keopscore
 from os.path import join
 import re
+import platform
 
 
 def KeOps_Print(message, force_print=False, **kwargs):
@@ -35,7 +36,7 @@ def KeOps_Error(message, show_line_number=True):
     raise ValueError(message)
 
 
-def KeOps_OS_Run(command):
+def KeOps_OS_Run(command, print_warning=True):
     import sys
 
     python_version = sys.version_info
@@ -43,20 +44,41 @@ def KeOps_OS_Run(command):
         import subprocess
 
         out = subprocess.run(command, shell=True, capture_output=True)
-        if out.stderr != b"":
+        if out.stderr != b"" and print_warning:
             KeOps_Warning("There were warnings or errors :", newline=True)
             KeOps_Print(out.stderr.decode("utf-8"))
     elif python_version >= (3, 5):
         import subprocess
 
-        subprocess.run(
+        out = subprocess.run(
             command,
             shell=True,
         )
     else:
-        import os
+        KeOps_Error("Python version >= 3.5 required.", newline=True)
+    return out
+
 
-        os.system(command)
+def get_include_file_abspath(filename, compiler):
+    out = KeOps_OS_Run(
+        f'echo "#include <{filename}>" | {compiler} -M -E -x c++ - | head -n 2'
+    )
+    strings = out.stdout.decode("utf8").split()
+    abspath = None
+    for s in strings:
+        if filename in s:
+            abspath = s
+    return abspath
+
+
+def get_brew_prefix():
+    """Get Homebrew prefix path using KeOps_OS_Run"""
+    if platform.system() != "Darwin":
+        return None
+    out = KeOps_OS_Run(f"brew --prefix", print_warning=False)
+    if out.stderr != b"":
+        return None
+    return out.stdout.decode("utf-8").strip()
 
 
 def find_library_abspath(lib):
diff --git a/pytest.sh b/pytest.sh
index 0f746f8be..3b56ed1e3 100755
--- a/pytest.sh
+++ b/pytest.sh
@@ -64,7 +64,7 @@ PROJDIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
 PYTHON="python3"
 
 # python environment for test
-TEST_VENV=${PROJDIR}/.test_venv
+TEST_VENV=${PROJDIR}/.test_venv_pytest
 
 # python test requirements (names of packages to be installed with pip)
 TEST_REQ="pip"