[core] Rez plugins: Ensure dependencies for meshroom_compute are present

`psutil` is a dependency of `meshroom_compute`, which cannot run if it
is not part of the environment. For rez plugins, if `psutil` is not
already part of the plugin's environment, it is added. No version is
specified so it can be resolved in the environment, without being aligned
on Meshroom's.

Author: cbentejac

meshroom/core/desc/node.py

@@ -17,6 +17,7 @@
 
 _MESHROOM_ROOT = Path(meshroom.__file__).parent.parent.as_posix()
 _MESHROOM_COMPUTE = (Path(_MESHROOM_ROOT) / "bin" / "meshroom_compute").as_posix()
+_MESHROOM_COMPUTE_DEPS = ["psutil"]
 
 
 class MrNodeType(enum.Enum):

meshroom/core/plugins.py

@@ -14,7 +14,7 @@
 
 from meshroom.common import BaseObject
 from meshroom.core import desc
-from meshroom.core.desc.node import _MESHROOM_ROOT
+from meshroom.core.desc.node import _MESHROOM_ROOT, _MESHROOM_COMPUTE_DEPS
 
 
 def validateNodeDesc(nodeDesc: desc.Node) -> list:
@@ -158,10 +158,10 @@ def __init__(self, folder: str, configEnv: dict[str: str], uri: str = ""):
 
     def resolveRezSubrequires(self) -> list[str]:
         """
-        Return the list of packages defined for the node execution. These execution packages are named
-        subrequires.
-        Note: If a package does not have a version number, the version is aligned with the main Meshroom
-        environment (if this package is defined).
+        Return the list of packages defined for the node execution. These execution packages are
+        named subrequires.
+        Note: If a package does not have a version number, the version is aligned with the main
+        Meshroom environment (if this package is defined).
         """
         subrequires = os.environ.get(f"{self.uri.upper()}_SUBREQUIRES", "").split(os.pathsep)
         packages = []
@@ -194,6 +194,15 @@ def resolveRezSubrequires(self) -> list[str]:
                 if not definedInParentEnv:
                     packages.append(package)
 
+        for package in _MESHROOM_COMPUTE_DEPS:
+            # For packages that are required by meshroom_compute, do not specify any version
+            # or align it with Meshroom's: the version will be found during the resolution of
+            # the environment based on the other packages.
+            # If any of these packages is already part of the environment a plugin's dependency,
+            # do not add it
+            if not package in " ".join(packages):
+                packages.append(package)
+
         logging.debug("Packages for the execution environment: " + ", ".join(packages))
         return packages