fix: sbatch stderr parsing (#161)

will hopefully fix #157 

The issue is, that submission joined `stderr` and `stdout` of the
`sbatch` call. Without add-ons `sbatch` only emits to `stdout` and to
`stderr` only in the case of an error. However, admins can add
informative messages to `stderr`, when this occurs, parsing the message
for the JobID failed. Now, `stderr` and `stdout` are considered
separately.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Enhanced error handling during SLURM job submission, providing clearer
feedback on failures.
	- Improved job ID retrieval by stripping whitespace from the output.

- **Bug Fixes**
- Addressed issues with job submission failures by capturing both
standard output and error messages.

- **Chores**
- Minor adjustments to logging for better clarity during job submission
and error reporting.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Filipe G. Vieira <1151762+fgvieira@users.noreply.github.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: 3 people

snakemake_executor_plugin_slurm/__init__.py

@@ -217,20 +217,35 @@ def run_job(self, job: JobExecutorInterface):
 
         self.logger.debug(f"sbatch call: {call}")
         try:
-            out = subprocess.check_output(
-                call, shell=True, text=True, stderr=subprocess.STDOUT
-            ).strip()
+            process = subprocess.Popen(
+                call,
+                shell=True,
+                text=True,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+            )
+            out, err = process.communicate()
+            if process.returncode != 0:
+                raise subprocess.CalledProcessError(
+                    process.returncode, call, output=err
+                )
         except subprocess.CalledProcessError as e:
             raise WorkflowError(
                 f"SLURM job submission failed. The error message was {e.output}"
             )
+        if err:  # any other error message?
+            raise WorkflowError(
+                f"SLURM job submission failed. The error message was {err}"
+            )
 
         # multicluster submissions yield submission infos like
         # "Submitted batch job <id> on cluster <name>" by default, but with the
         # --parsable option it simply yields "<id>;<name>".
         # To extract the job id we split by semicolon and take the first element
         # (this also works if no cluster name was provided)
-        slurm_jobid = out.split(";")[0]
+        slurm_jobid = out.strip().split(";")[0]
+        if not slurm_jobid:
+            raise WorkflowError("Failed to retrieve SLURM job ID from sbatch output.")
         slurm_logfile = slurm_logfile.replace("%j", slurm_jobid)
         self.logger.info(
             f"Job {job.jobid} has been submitted with SLURM jobid {slurm_jobid} "