Limit accelerator installations to GPU only

eb_hooks.py

@@ -422,6 +422,37 @@ def pre_fetch_hook(self, *args, **kwargs):
     if cpu_target == CPU_TARGET_ZEN4:
         pre_fetch_hook_zen4_gcccore1220(self, *args, **kwargs)
 
+    # Always check the software installation path
+    pre_fetch_hook_check_installation_path(self, *args, **kwargs)
+
+
+# Check the installation path so we verify that accelerator software always gets installed into the correct location
+def pre_fetch_hook_check_installation_path(self, *args, **kwargs):
+    # When we know the CUDA status, we will need to verify the installation path
+    # if we are doing an EESSI or host_injections installation
+    accelerator_deps = ['CUDA']
+    strict_eessi_installation = (
+        bool(re.search(EESSI_INSTALLATION_REGEX, self.installdir)) or
+        self.installdir.startswith(HOST_INJECTIONS_LOCATION))
+    if strict_eessi_installation:
+        dependency_names = self.cfg.dependency_names()
+        if self.cfg.name in accelerator_deps or any(dep in dependency_names for dep in accelerator_deps):
+            # Make sure the path is an accelerator location
+            if "/accel/" not in self.installdir:
+                raise EasyBuildError(
+                    f"It seems you are trying to install an accelerator package {self.cfg.name} into a "
+                    f"non-accelerator location {self.installdir}. You need to reconfigure your installation to target "
+                    "the correct location."
+                    )
+        else:
+            # If we don't have an accelerator dependency then we should be in a CPU installation path
+            if "/accel/" in self.installdir:
+                raise EasyBuildError(
+                    f"It seems you are trying to install a CPU-only package {self.cfg.name} into accelerator location "
+                    f"{self.installdir}. If this is a dependency of the package you are really interested in you will "
+                    "need to first install the CPU-only dependencies of that package."
+                    )
+
 
 def pre_fetch_hook_zen4_gcccore1220(self, *args, **kwargs):
     """Use --force --module-only if building a foss-2022b-based EasyConfig for Zen4.