Fix empty nodelist in PBS

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 - File transfer examples with .NET
+- Fix error for PBS jobs when no nodes are assigned to it.
 
 ## [2.4.1]
 
@@ -57,7 +58,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-- Fixed Slurm sacct integration and data parsing. 
+- Fixed Slurm sacct integration and data parsing.
 
 - Docker Compose startup: Added dependency for Slurm to wait for Keycloak health check before starting, preventing JWT certificate download failures.
 - Upload and Download transfer endpoints now require to specify transfer directives

src/lib/scheduler_clients/pbs/models.py

@@ -118,6 +118,11 @@ def __init__(self, **kwargs):
     @field_validator("nodes", mode="before")
     @classmethod
     def _parse_nodelist(cls, v):
+        if v is None or v == "":
+            # This string has been chosen to keep compatibility with the
+            # Slurm scheduler.
+            return "None assigned"
+
         nodes = []
         for chunk in v.split("+"):
             host = chunk.split("/")[0]  # drop the “/0”
@@ -131,6 +136,11 @@ def _parse_nodelist(cls, v):
                 nodes.append(host)
         return ",".join(nodes)
 
+    @field_validator("account", mode="before")
+    @classmethod
+    def cast_account_to_str(cls, v):
+        return str(v)
+
 
 class PbsNode(NodeModel):
     cpus: int = Field(alias=AliasChoices("pcpus"))