Updated README

Author: AlexanderSchultheiss

INSTALL.md

@@ -99,13 +99,18 @@ The aggregated results of the validation can be found in the following files.
 
 ## Troubleshooting
 
-### Got permission denied while trying to connect to the Docker daemon socket
+### 'Got permission denied while trying to connect to the Docker daemon socket'
 `Problem:` This is a common problem under Linux, if the user trying to execute Docker commands does not have the permissions to do so. 
 
 `Fix:` You can fix this problem by either following the [post-installation instructions](https://docs.docker.com/engine/install/linux-postinstall/), or by executing the scripts in the replication package with elevated permissions (i.e., `sudo`)
 
-### Unable to find image 'replication-package:latest' locally
+### 'Unable to find image 'replication-package:latest' locally'
 `Problem:` The Docker container could not be found. This either means that the name of the container that was built does not fit the name of the container that is being executed (this only happens if you changed the provided scripts), or that the Docker container was not built yet. 
 
 `Fix:` Build the Docker container.
 
+### No results after validation, or 'cannot create directory '../results/difftrees': Permission denied'
+`Problem:` This problem can occur due to how permissions are managed inside the Docker container. More specifically, it will appear, if Docker is executed with elevated permissions (i.e., `sudo`) and if there is no [results](results) directory because it was deleted manually. In this case, Docker will create the directory with elevated permissions, and the Docker user has no permissions to access the directory.
+
+`Fix:` If there is a _results_ directory delete it (e.g., via your file explorer). 
+Then, create a new _results_ directory without elevated permissions, or execute `git restore .` to restore the deleted directory.

docker/execute.sh

@@ -23,7 +23,7 @@ if [ "$1" == 'replication' ] || [ "$1" == 'validation' ]; then
   java -cp DiffDetectiveRunner.jar mining.FindMedianCommitTime ../results/difftrees
   java -cp DiffDetectiveRunner.jar mining.tablegen.MiningResultAccumulator ../results/difftrees ../results/difftrees
   python3 plotting/plot.py
-  cp ./runtime_histogram.png ../results/
+  cp ./runtime_histogram.png ../results/ || exit
   echo "The results are located in the 'results' directory."
 elif [ "$1" == 'proofs' ]; then
   echo "Running the proofs"