diff --git a/.github/workflows/testing-all-oses.yml b/.github/workflows/testing-all-oses.yml
index 34209bb50..abbb0829e 100644
--- a/.github/workflows/testing-all-oses.yml
+++ b/.github/workflows/testing-all-oses.yml
@@ -22,10 +22,10 @@ jobs:
           sed -n '/^requirements:/,/^test:/p' |
           sed -e "s/.*- //" |
           sed -e "s/menuinst.*//" |
-          sed -e "s/.*://" > requirements.txt
-        cat requirements.d/development.txt >> requirements.txt
-        sed -i '/^$/d' requirements.txt
-        sed -i '/^#.*$/d' requirements.txt
+          sed -e "s/.*://" > requirements.tmp.txt
+        cat requirements.d/development.txt >> requirements.tmp.txt
+        sed -e '/^$/d' -e '/^#.*$/d' requirements.tmp.txt > requirements.txt
+        rm requirements.tmp.txt
         cat requirements.txt
     - uses: mamba-org/setup-micromamba@v1
       with:
@@ -41,5 +41,5 @@ jobs:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       run: |
         git config --global --add safe.directory /__w/MSS/MSS
-        mamba install coveralls
-        coveralls --service=github
+        micromamba install -n ci coveralls
+        micromamba run -n ci coveralls --service=github