fix(errors): detect missing CMake link targets

Author: GaspardKirira

src/cmake/CMakeBuild.cpp

@@ -426,6 +426,58 @@ namespace vix::cli::build
       currentProgressLine.clear();
     };
 
+    auto is_failed_line = [](const std::string &line) -> bool
+    {
+      return line.rfind("FAILED:", 0) == 0;
+    };
+
+    auto looks_like_live_error_line = [&](const std::string &line) -> bool
+    {
+      if (line.empty())
+        return false;
+
+      if (is_failed_line(line))
+        return true;
+
+      if (line.rfind("ninja:", 0) == 0)
+        return true;
+
+      if (line.find(": error:") != std::string::npos)
+        return true;
+
+      if (line.find(" error: ") != std::string::npos)
+        return true;
+
+      if (line.find("fatal error:") != std::string::npos)
+        return true;
+
+      if (line.find("undefined reference to") != std::string::npos)
+        return true;
+
+      if (line.find("collect2: error:") != std::string::npos)
+        return true;
+
+      if (line.find("ld: error:") != std::string::npos)
+        return true;
+
+      if (line.find("CMake Error") != std::string::npos)
+        return true;
+
+      if (line.rfind("-->", 0) == 0)
+        return true;
+
+      if (line == "code:")
+        return true;
+
+      if (line.rfind("hint:", 0) == 0)
+        return true;
+
+      if (line.rfind("at:", 0) == 0)
+        return true;
+
+      return false;
+    };
+
     auto should_echo_line = [&](const std::string &line) -> bool
     {
       if (quiet)
@@ -437,6 +489,9 @@ namespace vix::cli::build
       if (!progressOnly)
         return true;
 
+      if (line == "ninja: build stopped: subcommand failed.")
+        return false;
+
       if (line == "ninja: no work to do.")
         return false;
 
@@ -446,13 +501,7 @@ namespace vix::cli::build
       if (line.find("Copy compile_commands.json to project root") != std::string::npos)
         return false;
 
-      if (line.rfind("FAILED:", 0) == 0)
-        return true;
-
-      if (line.rfind("ninja:", 0) == 0)
-        return true;
-
-      return false;
+      return looks_like_live_error_line(line);
     };
 
     std::string buf(16 * 1024, '\0');

src/errors/build/CMakeBuildErrors.cpp

@@ -1,6 +1,6 @@
 /**
  *
- *  @file CMakeBuildErrors.hpp
+ *  @file CMakeBuildErrors.cpp
  *  @author Gaspard Kirira
  *
  *  Copyright 2025, Gaspard Kirira.  All rights reserved.
@@ -12,34 +12,89 @@
  *
  */
 #include <vix/cli/errors/build/CMakeBuildErrors.hpp>
-
 #include <iostream>
+#include <regex>
 #include <string>
-
+#include <string_view>
+#include <iostream>
 #include <vix/cli/Style.hpp>
 
 using namespace vix::cli::style;
 
 namespace vix::cli::errors::build
 {
-  bool handleCMakeBuildError(std::string_view log)
+  namespace
   {
-    const bool cacheDirMismatch =
-        log.find("The current CMakeCache.txt directory") != std::string_view::npos;
+    bool handle_cache_mismatch(std::string_view log)
+    {
+      const bool cacheDirMismatch =
+          log.find("The current CMakeCache.txt directory") != std::string_view::npos;
+      const bool sourceMismatch =
+          log.find("does not match the source") != std::string_view::npos &&
+          log.find("used to generate cache") != std::string_view::npos;
+
+      if (!cacheDirMismatch && !sourceMismatch)
+        return false;
+
+      error("CMake configure failed: stale build cache detected.");
+      hint("Your build directory was generated from another project location.");
+      hint("Remove the old build directory and reconfigure.");
+      hint("Recommended: vix build --clean");
+      hint("Manual fix: rm -rf build-ninja build-dev build-release");
+      return true;
+    }
+
+    bool handle_missing_link_target(std::string_view log)
+    {
+      const bool hasMissingTarget =
+          log.find("but the target was not found") != std::string_view::npos &&
+          log.find("target_link_libraries") != std::string_view::npos;
+
+      if (!hasMissingTarget)
+        return false;
+
+      std::string targetName;
+      std::string missingLink;
+
+      {
+        const std::regex reTarget(R"re(Target\s+"([^"]+)")re");
+        std::match_results<std::string_view::const_iterator> m;
 
-    const bool sourceMismatch =
-        log.find("does not match the source") != std::string_view::npos &&
-        log.find("used to generate cache") != std::string_view::npos;
+        if (std::regex_search(log.begin(), log.end(), m, reTarget) && m.size() >= 2)
+          targetName = m[1].str();
+      }
 
-    if (!cacheDirMismatch && !sourceMismatch)
-      return false;
+      {
+        const std::regex reMissing(R"re(links\s+to:\s*\n\s*\n\s*([^\s][^\n]*))re");
+        std::match_results<std::string_view::const_iterator> m;
 
-    error("CMake configure failed: stale build cache detected.");
-    hint("Your build directory was generated from another project location.");
-    hint("Remove the old build directory and reconfigure.");
-    hint("Recommended: vix build --clean");
-    hint("Manual fix: rm -rf build-ninja build-dev build-release");
+        if (std::regex_search(log.begin(), log.end(), m, reMissing) && m.size() >= 2)
+          missingLink = m[1].str();
+      }
 
-    return true;
+      error("Build failed: unresolved CMake target.");
+
+      if (!targetName.empty())
+        std::cerr << "    target: " << targetName << "\n";
+
+      if (!missingLink.empty())
+        std::cerr << "    missing: " << RED << missingLink << RESET << "\n";
+
+      std::cerr << "\n";
+      hint("Fix the target name or make sure it is defined before linking.");
+
+      return true;
+    }
+
+  } // namespace
+
+  bool handleCMakeBuildError(std::string_view log)
+  {
+    if (handle_cache_mismatch(log))
+      return true;
+    if (handle_missing_link_target(log))
+      return true;
+    return false;
   }
-}
+
+} // namespace vix::cli::errors::build