Avoid exception in get_gpu_info

Currently the function calls `run_cmd` which throws on error AND checks
the exit code which is redundant and causes a log message
`"ERROR EasyBuild crashed with an error ..."` to be logged on error
which is confusing as e.g it is VERY unlikely both `nvidia-smi` and
`rocm-smi` are on the system.
So check for existance first and suppress output and error checking of `run_cmd`.

easybuild/tools/systemtools.py

@@ -59,6 +59,7 @@
 
 from easybuild.base import fancylogger
 from easybuild.tools.build_log import EasyBuildError, print_warning
+from easybuild.tools.config import IGNORE
 from easybuild.tools.filetools import is_readable, read_file, which
 from easybuild.tools.py2vs3 import OrderedDict, string_type
 from easybuild.tools.run import run_cmd
@@ -608,14 +609,19 @@ def get_gpu_info():
     """
     Get the GPU info
     """
-    gpu_info = {}
-    os_type = get_os_type()
+    if get_os_type() != LINUX:
+        _log.info("Only know how to get GPU info on Linux, assuming no GPUs are present")
+        return {}
 
-    if os_type == LINUX:
+    gpu_info = {}
+    if not which('nvidia-smi', on_error=IGNORE):
+        _log.info("nvidia-smi not found. Cannot detect NVIDIA GPUs")
+    else:
         try:
             cmd = "nvidia-smi --query-gpu=gpu_name,driver_version --format=csv,noheader"
             _log.debug("Trying to determine NVIDIA GPU info on Linux via cmd '%s'", cmd)
-            out, ec = run_cmd(cmd, force_in_dry_run=True, trace=False, stream_output=False)
+            out, ec = run_cmd(cmd, simple=False, log_ok=False, log_all=False,
+                              force_in_dry_run=True, trace=False, stream_output=False)
             if ec == 0:
                 for line in out.strip().split('\n'):
                     nvidia_gpu_info = gpu_info.setdefault('NVIDIA', {})
@@ -627,16 +633,21 @@ def get_gpu_info():
             _log.debug("Exception was raised when running nvidia-smi: %s", err)
             _log.info("No NVIDIA GPUs detected")
 
+    if not which('rocm-smi', on_error=IGNORE):
+        _log.info("rocm-smi not found. Cannot detect AMD GPUs")
+    else:
         try:
             cmd = "rocm-smi --showdriverversion --csv"
             _log.debug("Trying to determine AMD GPU driver on Linux via cmd '%s'", cmd)
-            out, ec = run_cmd(cmd, force_in_dry_run=True, trace=False, stream_output=False)
+            out, ec = run_cmd(cmd, simple=False, log_ok=False, log_all=False,
+                              force_in_dry_run=True, trace=False, stream_output=False)
             if ec == 0:
                 amd_driver = out.strip().split('\n')[1].split(',')[1]
 
             cmd = "rocm-smi --showproductname --csv"
             _log.debug("Trying to determine AMD GPU info on Linux via cmd '%s'", cmd)
-            out, ec = run_cmd(cmd, force_in_dry_run=True, trace=False, stream_output=False)
+            out, ec = run_cmd(cmd, simple=False, log_ok=False, log_all=False,
+                              force_in_dry_run=True, trace=False, stream_output=False)
             if ec == 0:
                 for line in out.strip().split('\n')[1:]:
                     amd_card_series = line.split(',')[1]
@@ -650,8 +661,6 @@ def get_gpu_info():
         except Exception as err:
             _log.debug("Exception was raised when running rocm-smi: %s", err)
             _log.info("No AMD GPUs detected")
-    else:
-        _log.info("Only know how to get GPU info on Linux, assuming no GPUs are present")
 
     return gpu_info