Document that SETENV is needed with sudo, and provide error info when…

… gauge-adapter parsing fails (#211)

README.md

@@ -86,7 +86,7 @@ To reduce noise generated by the system, `rebench-denoise` depends on:
 
  - `sudo` rights. `rebench` will attempt to determine suitable configuration
    parameters and suggest them. This includes allowing the execution of `rebench-denoise`
-   via `sudo` without password.
+   via `sudo` without password and with the permission to set environment variables (`SETENV`).
  - [`cpuset`](https://github.com/lpechacek/cpuset/) to reserve cores for benchmarking.
    On Ubuntu: `apt install cpuset`
 

rebench/denoise.py

@@ -105,7 +105,7 @@ def minimize_noise(show_warnings, ui, for_profiling):  # pylint: disable=too-man
                    + ' can be used without password.\n'
             msg += '{ind}To be able to run rebench-denoise without password,\n'
             msg += '{ind}add the following to the end of your sudoers file (using visudo):\n'
-            msg += '{ind}{ind}' + getpass.getuser() + ' ALL = (root) NOPASSWD: '\
+            msg += '{ind}{ind}' + getpass.getuser() + ' ALL = (root) NOPASSWD:SETENV: '\
                    + denoise_cmd + '\n'
         elif 'command not found' in output:
             msg += '{ind}Please make sure `rebench-denoise` is on the PATH\n'

rebench/executor.py

@@ -30,7 +30,8 @@
 from time import time
 
 from . import subprocess_with_timeout as subprocess_timeout
-from .interop.adapter import ExecutionDeliveredNoResults, instantiate_adapter
+from .interop.adapter import ExecutionDeliveredNoResults, instantiate_adapter, OutputNotParseable, \
+    ResultsIndicatedAsInvalid
 from .ui import escape_braces
 
 
@@ -551,7 +552,11 @@ def _eval_output(self, output, run_id, gauge_adapter, cmdline):
 
             run_id.indicate_successful_execution()
             self.ui.verbose_output_info(msg, run_id, cmdline)
-        except ExecutionDeliveredNoResults:
+        except ExecutionDeliveredNoResults as e:
+            if isinstance(e, OutputNotParseable):
+                self.ui.error("{ind}Output of run could not be parsed.\n", run_id, cmdline)
+            elif isinstance(e, ResultsIndicatedAsInvalid):
+                self.ui.error("{ind}Results were marked as invalid.\n", run_id, cmdline)
             run_id.indicate_failed_execution()
             run_id.report_run_failed(cmdline, 0, output)