Fixed: Lidarr failing to start on linux if `which` missing (#714)

Fix startup failure when `which` missing

src/NzbDrone.Core/Parser/FingerprintingService.cs

@@ -56,13 +56,22 @@ namespace NzbDrone.Core.Parser
 
             _customerRequestBuilder = new HttpRequestBuilder(_acoustIdUrl).CreateFactory();
 
+            // An exception here will cause Lidarr to fail to start, so catch any errors
+            try
+            {
                 _fpcalcPath = GetFpcalcPath();
+
                 if (_fpcalcPath.IsNotNullOrWhiteSpace())
                 {
                     _fpcalcVersion = GetFpcalcVersion();
                     _fpcalcArgs = GetFpcalcArgs();
                 }
             }
+            catch (Exception ex)
+            {
+                _logger.Error(ex, "Somthing went wrong detecting fpcalc");
+            }
+        }
 
         public bool IsSetup() => _fpcalcPath.IsNotNullOrWhiteSpace();
         public Version FpcalcVersion() => _fpcalcVersion;
@@ -77,17 +86,19 @@ namespace NzbDrone.Core.Parser
 
                 // check that the command exists
                 Process p = new Process();
-                p.StartInfo.FileName = "which";
+                p.StartInfo.FileName = path;
-                p.StartInfo.Arguments = $"{path}";
+                p.StartInfo.Arguments = "-version";
                 p.StartInfo.UseShellExecute = false;
                 p.StartInfo.RedirectStandardOutput = true;
 
+                try
+                {
                     p.Start();
                     // To avoid deadlocks, always read the output stream first and then wait.
                     string output = p.StandardOutput.ReadToEnd();
                     p.WaitForExit(1000);
-
+                }
-                if (p.ExitCode != 0)
+                catch
                 {
                     _logger.Debug("fpcalc not found");
                     return null;