CI: provide linter output as artifacts

.github/workflows/pr.yaml

@@ -111,6 +111,10 @@ jobs:
         mode: lint
         repository-list: ${{ needs.setup.outputs.repository-list }}
         tool-list: ${{ needs.setup.outputs.tool-list }}
+    - uses: actions/upload-artifact@v2
+      with:
+        name: 'Tool linting output'
+        path: lint_report.txt
 
   # flake8 of Python scripts in the changed repositories
   flake8:
@@ -138,7 +142,11 @@ jobs:
     - name: Install flake8
       run: pip install flake8 flake8-import-order
     - name: Flake8
-      run: echo '${{ needs.setup.outputs.repository-list }}' | xargs -d '\n' flake8
+      run: echo '${{ needs.setup.outputs.repository-list }}' | xargs -d '\n' flake8 --output-file y --tee
+    - uses: actions/upload-artifact@v2
+      with:
+        name: 'Python linting output'
+        path: pylint_report.txt
 
   lintr:
     name: Lint R scripts
@@ -186,12 +194,16 @@ jobs:
             status <- 1
             for (l in lnt) {
               rel_path <- paste(repo, l$filename, sep="/")
-              write(paste(paste(rel_path, l$line_number, l$column_number, sep=":"), l$message), stderr())
+              write(paste(paste(rel_path, l$line_number, l$column_number, sep=":"), l$message), stdout())
             }
           }
         }
         quit(status = status)
-      shell: Rscript {0}
+      shell: Rscript {0} | tee rlint_report.txt
+    - uses: actions/upload-artifact@v2
+      with:
+        name: 'R linting output'
+        path: rlint_report.txt
 
   # Planemo test the changed repositories, each chunk creates an artifact
   # containing HTML and JSON reports for the executed tests