diff --git a/README.md b/README.md
index 712582fba20465c30d54b280cde9a94ad834d7f7..1125cf37963154650ce10e1d7c2840f690139404 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,20 @@ make all
 ```
 Now run the two scripts first `./server.sh` and then `./client.sh` in two separate terminal windows to observe that the clients (the MPI-processes) inform the server of their identity an then the server answers with modified ranks which the client then applies, completing it's initialization.
 
+## Troubleshooting
+
+### MPI not found
+
+If running `./client.sh` causes the following error:
+```shell
+./client.sh: Zeile 21: mpirun: Command not found.
+```
+Then the problem is caused by MPI not being found.
+In this case the `OMPI` and `PATH` variables are not properly set.
+They need to point to the Open MPI installation directory (as set in the `--prefix` of the `configure` call at the installation).
+
+---
+
 **Now follows the actual/default Open MPI README:**
 
 # Open MPI
@@ -94,48 +108,49 @@ $ ../configure --prefix=<path> |& tee config.out
 
 The rest of this file contains:
 
-* [General release notes about Open MPI](#general-notes)
-  * [Platform-specific notes](#platform-notes)
-  * [Compiler-specific notes](#compiler-notes)
-  * [Run-time support notes](#general-run-time-support-notes)
-  * [MPI functionality and features](#mpi-functionality-and-features)
-  * [OpenSHMEM functionality and
-    features](#openshmem-functionality-and-features)
-  * [MPI collectives](#mpi-collectives)
-  * [OpenSHMEM collectives](#openshmem-collectives)
-  * [Network support](#network-support)
-  * [Open MPI extensions](#open-mpi-extensions)
-* [Detailed information on building Open MPI](#building-open-mpi)
-  * [Installation options](#installation-options)
-  * [Networking support and options](#networking-support--options)
-  * [Run-time system support and options](#run-time-system-support)
-  * [Miscellaneous support
-    libraries](#miscellaneous-support-libraries)
-  * [MPI functionality options](#mpi-functionality)
-  * [OpenSHMEM functionality options](#openshmem-functionality)
-  * [Miscellaneous functionality
-    options](#miscellaneous-functionality)
-* [Open MPI version and library numbering
-  policies](#open-mpi-version-numbers-and-binary-compatibility)
-  * [Backwards compatibility polices](#backwards-compatibility)
-  * [Software version numbering](#software-version-number)
-  * [Shared library version numbering](#shared-library-version-number)
-* [Information on how to both query and validate your Open MPI
-  installation](#checking-your-open-mpi-installation)
-* [Description of Open MPI extensions](#open-mpi-api-extensions)
-  * [Compiling the extensions](#compiling-the-extensions)
-  * [Using the extensions](#using-the-extensions)
-* [Examples showing how to compile Open MPI applications](#compiling-open-mpi-applications)
-* [Examples showing how to run Open MPI applications](#running-open-mpi-applications)
-* [Summary information on the various plugin
- frameworks](#the-modular-component-architecture-mca)
-  * [MPI layer frameworks](#mpi-layer-frameworks)
-  * [OpenSHMEM component frameworks](#openshmem-component-frameworks)
-  * [Run-time environment
-    frameworks](#back-end-run-time-environment-rte-component-frameworks)
-  * [Miscellaneous frameworks](#miscellaneous-frameworks)
-  * [Other notes about frameworks](#framework-notes)
-* [How to get more help](#questions--problems)
+- [Custom Open MPI](#custom-open-mpi)
+  - [Building](#building)
+  - [Usage](#usage)
+  - [Troubleshooting](#troubleshooting)
+    - [MPI not found](#mpi-not-found)
+- [Open MPI](#open-mpi)
+  - [Quick start](#quick-start)
+  - [Table of contents](#table-of-contents)
+  - [General notes](#general-notes)
+    - [Platform Notes](#platform-notes)
+    - [Compiler Notes](#compiler-notes)
+    - [General Run-Time Support Notes](#general-run-time-support-notes)
+    - [MPI Functionality and Features](#mpi-functionality-and-features)
+    - [OpenSHMEM Functionality and Features](#openshmem-functionality-and-features)
+    - [MPI Collectives](#mpi-collectives)
+    - [OpenSHMEM Collectives](#openshmem-collectives)
+    - [Network Support](#network-support)
+    - [Open MPI Extensions](#open-mpi-extensions)
+  - [Building Open MPI](#building-open-mpi)
+    - [Installation Options](#installation-options)
+    - [Networking support / options](#networking-support--options)
+    - [Run-time system support](#run-time-system-support)
+    - [Miscellaneous support libraries](#miscellaneous-support-libraries)
+    - [MPI Functionality](#mpi-functionality)
+    - [OpenSHMEM Functionality](#openshmem-functionality)
+    - [Miscellaneous Functionality](#miscellaneous-functionality)
+  - [Open MPI Version Numbers and Binary Compatibility](#open-mpi-version-numbers-and-binary-compatibility)
+    - [Backwards Compatibility](#backwards-compatibility)
+    - [Software Version Number](#software-version-number)
+    - [Shared Library Version Number](#shared-library-version-number)
+  - [Checking Your Open MPI Installation](#checking-your-open-mpi-installation)
+  - [Open MPI API Extensions](#open-mpi-api-extensions)
+    - [Compiling the extensions](#compiling-the-extensions)
+    - [Using the extensions](#using-the-extensions)
+  - [Compiling Open MPI Applications](#compiling-open-mpi-applications)
+  - [Running Open MPI Applications](#running-open-mpi-applications)
+  - [The Modular Component Architecture (MCA)](#the-modular-component-architecture-mca)
+    - [MPI layer frameworks](#mpi-layer-frameworks)
+    - [OpenSHMEM component frameworks](#openshmem-component-frameworks)
+    - [Back-end run-time environment (RTE) component frameworks:](#back-end-run-time-environment-rte-component-frameworks)
+    - [Miscellaneous frameworks:](#miscellaneous-frameworks)
+    - [Framework notes](#framework-notes)
+  - [Questions?  Problems?](#questions--problems)
 
 Also, note that much, much more information is also available [in the
 Open MPI FAQ](https://www.open-mpi.org/faq/).
diff --git a/ompi/communicator/comm_init.c b/ompi/communicator/comm_init.c
index 9af7d941bcebfb85ee096e849fe907ab80c3ec8b..23fe6646e16ad55960efc7a8df804c3003735def 100644
--- a/ompi/communicator/comm_init.c
+++ b/ompi/communicator/comm_init.c
@@ -35,6 +35,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <sys/un.h>
 #include <unistd.h>
 #include <string.h>
@@ -57,6 +58,8 @@
 #define FD_STDIN 0
 #define BUFFLEN 128
 
+#define JOBID_ENV_VAR "SLURM_VRM_JOBID"
+
 /*
 ** Table for Fortran <-> C communicator handle conversion
 ** Also used by P2P code to lookup communicator based
@@ -141,11 +144,20 @@ static int get_modified_ranks(uint32_t jobid, uint32_t vpid, size_t size, opal_v
 
     pid_t pid = getpid();
 
+    const char * vrm_jobid = getenv(JOBID_ENV_VAR);
+    char vrm_jobid_with_leading_comma[sizeof(uint64_t) + 1] = "";
+    if (NULL != vrm_jobid) {
+        char comma = ',';
+        strncat(vrm_jobid_with_leading_comma, &comma, 1);
+        strcat(vrm_jobid_with_leading_comma, vrm_jobid);
+        printf("TEST: %s", vrm_jobid_with_leading_comma);
+    }
+
     char info_to_send[BUFFLEN];
     memset(info_to_send, 0, BUFFLEN);
     snprintf(info_to_send, BUFFLEN,
-            "{\"msg_type\": 128, \"msg_data\": \"%d,%u,%u,%zu\"}",
-            pid, vpid, jobid, size);
+            "{\"msg_type\": 128, \"msg_data\": \"%d,%u,%u,%zu%s\"}",
+            pid, vpid, jobid, size, vrm_jobid_with_leading_comma);
 
     // TODO: endianness
     uint32_t msg_length = strlen(info_to_send) + 1;
diff --git a/rank-swapper-agent/locserv.c b/rank-swapper-agent/locserv.c
index 37ae142b36d4ce880b01044dddc0b76580d7bbc2..7c11f2867d12a94678db33eb4a38fe6fdf4af5cd 100644
--- a/rank-swapper-agent/locserv.c
+++ b/rank-swapper-agent/locserv.c
@@ -84,6 +84,9 @@ int main(void) {
         uint32_t jobid = 0;
         size_t size = 0;
         int vars_read = sscanf(client_message, "{\"msg_type\": 128, \"msg_data\": \"%d,%u,%u,%zu\"}", &pid, &vpid, &jobid, &size);
+        if (4 != vars_read) {
+            errorExit("Message could not be parsed: Too many/few entries in msg_data!");
+        }
         printf("Sscanf read count: %d (should equal 4)\n", vars_read);
         printf("Spawned - PID: %d, vpid: %u, jobID: %u, size: %zu\n", pid, vpid, jobid, size);