diff --git a/.github/workflows/gh-actions.yml b/.github/workflows/gh-actions.yml
index 8e12b44ac3..ad1f7d0b81 100644
--- a/.github/workflows/gh-actions.yml
+++ b/.github/workflows/gh-actions.yml
@@ -324,7 +324,7 @@ jobs:
       - run: apt-get update
       - run: apt -y install clang gcc-arm-embedded gcc-multilib make git wget unzip python3.8 python3.8-distutils python3.8-venv
       - run: python3.8 -m venv ./venv
-      - run: . venv/bin/activate
+      - run: source ./venv/bin/activate
       - run: make -f ./targets/os/riot/Makefile.travis install-noapt
       - run: make -f ./targets/os/riot/Makefile.travis script
 
diff --git a/tools/build.py b/tools/build.py
index 137c32b48f..55cdb48be6 100755
--- a/tools/build.py
+++ b/tools/build.py
@@ -22,6 +22,8 @@
 import sys
 import settings
 
+print(sys.version)
+
 def default_toolchain():
     # We don't have default toolchain on Windows and os.uname() isn't supported.
     if sys.platform == 'win32':