propogate ossgadget errors

src/Shared/PackageManagers/CargoProjectManager.cs

@@ -417,14 +417,9 @@ public override Uri GetPackageAbsoluteUri(PackageURL purl)
                 return null;
 
             }
-            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.InternalServerError)
-            {
-                Logger.Debug($"Unable to get published timestamp for package: {purl}, error: {ex.Message}");
-                return null;
-            }
-            catch (Exception ex)
+            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
             {
-                Logger.Debug(ex, "Error fetching PublishedTimeStamp: {0}", ex.Message);
+                Logger.Debug($"RSS feed not found for package: {purl}, error: {ex.Message}");
                 return null;
             }
         }

src/Shared/PackageManagers/MavenProjectManager.cs

@@ -274,7 +274,7 @@ public override async Task<bool> PackageVersionExistsAsync(PackageURL purl, bool
                 var baseUrl = $"{feedUrl.EnsureTrailingSlash()}{packageNamespace}/{packageName}/{purl.Version}/{packageName}-{purl.Version}.pom";
                 return await GetHttpStringCache(httpClient, baseUrl, useCache);
             }
-            catch (Exception ex)
+            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
             {
                 Logger.Warn(ex, $"Error fetching Maven metadata: {ex.Message}");
                 return null;

src/Shared/PackageManagers/NPMProjectManager.cs

@@ -380,7 +380,7 @@ public override async Task<IEnumerable<string>> EnumerateVersionsAsync(PackageUR
                 string? content = await GetHttpStringCache(httpClient, $"{ENV_NPM_API_ENDPOINT}/{packageName}", useCache);
                 return content;
             }
-            catch (Exception ex)
+            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
             {
                 Logger.Debug(ex, $"Error fetching NPM metadata: {ex.Message}");
                 return null;

src/Shared/PackageManagers/NuGetProjectManager.cs

@@ -18,6 +18,7 @@ namespace Microsoft.CST.OpenSource.PackageManagers
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
+    using System.Net;
     using System.Net.Http;
     using System.Text.Json;
     using System.Threading.Tasks;
@@ -149,7 +150,12 @@ private async Task<string> GetRegistrationEndpointAsync()
 
                 return JsonSerializer.Serialize(packageVersionMetadata);
             }
-            catch (Exception ex)
+            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
+            {
+                Logger.Debug(ex, $"Error fetching NuGet metadata: {ex.Message}");
+                return null;
+            }
+            catch (InvalidOperationException ex) when (purl.Version == null)
             {
                 Logger.Debug(ex, $"Error fetching NuGet metadata: {ex.Message}");
                 return null;

src/Shared/PackageManagers/PyPIProjectManager.cs

@@ -289,7 +289,7 @@ public override async Task<IEnumerable<string>> EnumerateVersionsAsync(PackageUR
 
                 return await GetHttpStringCache(httpClient, $"{ENV_PYPI_ENDPOINT}/pypi/{purl.Name}/json", useCache);
             }
-            catch (Exception ex)
+            catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
             {
                 Logger.Debug(ex, "Error fetching PyPI metadata: {0}", ex.Message);
                 return null;