diff --git a/benchkit/benches/speccpu2017/__init__.py b/benchkit/benches/speccpu2017/__init__.py
index 0e0fd098..744a4284 100644
--- a/benchkit/benches/speccpu2017/__init__.py
+++ b/benchkit/benches/speccpu2017/__init__.py
@@ -85,7 +85,7 @@
 from benchkit.core.bktypes.callresults import BuildResult, FetchResult, RunResult
 from benchkit.core.bktypes.contexts import BuildContext, CollectContext, FetchContext, RunContext
 from benchkit.dependencies.packages import PackageDependency
-from benchkit.utils.dir import benchkit_home_dir
+from benchkit.utils.dir import benchkit_home_dir, get_benches_dir
 from benchkit.utils.fetchtools import fuseiso_mount, fuseiso_umount, sed_edit
 
 
@@ -106,8 +106,8 @@ class SPECCPU2017Bench:
     def fetch(
         self,
         ctx: FetchContext,
-        parent_dir: Path,
         spec_source_iso: Path,
+        parent_dir: Path | None = None,
     ) -> FetchResult:
         """
         Install the SPEC CPU® 2017 suite into the bench workspace from a local ISO.
@@ -124,16 +124,17 @@ def fetch(
 
         Args:
             ctx: FetchContext providing platform and execution capabilities.
+            spec_source_iso: Path to the SPEC CPU 2017 ISO image to install from.
             parent_dir: Directory under which the SPEC installation directory
                 (`spec`) will be created/used.
-            spec_source_iso: Path to the SPEC CPU 2017 ISO image to install from.
 
         Returns:
             FetchResult with `src_dir` set to the installed SPEC directory
             (`<parent_dir>/spec`).
         """
-        mnt_dir = benchkit_home_dir() / "spec-mnt"
+        parent_dir = get_benches_dir(parent_dir=parent_dir)
         spec_dir = parent_dir / "spec"
+        mnt_dir = benchkit_home_dir() / "spec-mnt"
 
         comm = ctx.platform.comm
 
diff --git a/benchkit/commandwrappers/taskset.py b/benchkit/commandwrappers/taskset.py
index 9fac0602..335b30e4 100644
--- a/benchkit/commandwrappers/taskset.py
+++ b/benchkit/commandwrappers/taskset.py
@@ -50,7 +50,7 @@ def command_prefix(
         mtc = master_thread_core
 
         if self.set_all_cpus:
-            if cpu_order is None or nb_threads is None:
+            if cpu_order is None:
                 return []
 
             cpu_order_list = self.platform.cpu_order(provided_order=cpu_order)