Improve the error description of "Unable to find suitable version"

src/main/java/me/itzg/helpers/curseforge/CurseForgeInstaller.java

@@ -971,11 +971,12 @@ private void prepareModLoader(String id, String minecraftVersion) {
             throw new GenericException("Unknown modloader ID: " + id);
         }
 
+        final String provider = parts[0];
         final String loaderVersion = parts.length == 2 ? parts[1] : parts[2];
 
         try (SharedFetch sharedFetch = Fetch.sharedFetch("install-curseforge", sharedFetchOptions)) {
 
-            switch (parts[0]) {
+            switch (provider) {
                 case "forge":
                     prepareForge(sharedFetch, minecraftVersion, loaderVersion);
                     break;
@@ -989,8 +990,11 @@ private void prepareModLoader(String id, String minecraftVersion) {
                     break;
 
                 default:
-                    throw new InvalidParameterException(String.format("ModLoader %s is not yet supported", parts[0]));
+                    throw new InvalidParameterException(String.format("ModLoader %s is not yet supported", provider));
             }
+        } catch (InvalidParameterException e) {
+            throw new GenericException("Unable to prepare modpack's mod loader "
+                + provider + " " + loaderVersion + " for Minecraft " + minecraftVersion, e);
         }
     }
 

src/main/java/me/itzg/helpers/errors/ExceptionHandler.java

@@ -28,8 +28,8 @@ public int handleExecutionException(Exception e, CommandLine commandLine, ParseR
                 log.debug("Invalid parameter details", e);
             }
             else if (e instanceof FailedRequestException) {
-                logUnexpectedException(e, commandLine);
-                log.debug("Failed request details: {}", e.toString());
+                logExceptionWithoutStacktrace(e, commandLine);
+                log.debug("Failed request details", e);
             }
             else if (e instanceof RateLimitException) {
                 logUnexpectedException(e, commandLine);
@@ -55,4 +55,12 @@ private static void logUnexpectedException(Exception e, CommandLine commandLine)
             e
         );
     }
+
+    private static void logExceptionWithoutStacktrace(Exception e, CommandLine commandLine) {
+        log.error("'{}' command failed. Version is {}: {}",
+            commandLine.getCommandName(),
+            McImageHelper.getVersion(),
+            ExceptionDetailer.buildCausalMessages(e)
+        );
+    }
 }

src/main/java/me/itzg/helpers/forge/ForgeInstaller.java

@@ -53,7 +53,8 @@ public void install(
 
         final VersionPair resolved = installerResolver.resolve();
         if (resolved == null) {
-            throw new InvalidParameterException("Unable to find suitable version");
+            throw new InvalidParameterException("Unable to find suitable version for " +
+                installerResolver.getDescription());
         }
         log.debug("Resolved installer version={}", resolved);
 

src/main/java/me/itzg/helpers/forge/ForgeInstallerResolver.java

@@ -109,6 +109,11 @@ public void cleanup(Path forgeInstallerJar) {
         }
     }
 
+    @Override
+    public String getDescription() {
+        return String.format("Minecraft %s Forge %s", requestedMinecraftVersion, requestedForgeVersion);
+    }
+
     private PromotionsSlim loadPromotions() {
         return sharedFetch.fetch(URI.create(promotionsUrl))
             .userAgentCommand("forge")

src/main/java/me/itzg/helpers/forge/InstallerResolver.java

@@ -9,4 +9,6 @@ public interface InstallerResolver {
     Path download(String minecraftVersion, String forgeVersion, Path outputDir);
 
     void cleanup(Path forgeInstallerJar);
+
+    String getDescription();
 }

src/main/java/me/itzg/helpers/forge/NeoForgeInstallerResolver.java

@@ -223,4 +223,9 @@ public void cleanup(Path forgeInstallerJar) {
             log.warn("Failed to delete NeoForge installer", e);
         }
     }
+
+    @Override
+    public String getDescription() {
+        return String.format("Minecraft %s NeoForge %s", requestedMinecraftVersion, requestedNeoForgeVersion);
+    }
 }

src/main/java/me/itzg/helpers/forge/ProvidedInstallerResolver.java

@@ -50,6 +50,11 @@ public void cleanup(Path forgeInstallerJar) {
         // nothing needed
     }
 
+    @Override
+    public String getDescription() {
+        return String.format("Provided installer %s", forgeInstaller.toString());
+    }
+
     private VersionPair extractVersion(Path forgeInstaller) throws IOException {
 
         final VersionPair fromVersionJson = IoStreams.readFileFromZip(forgeInstaller, "version.json",