Better message when missing a required command line tool.

catkin_tools/jobs/catkin.py

@@ -37,6 +37,7 @@
 from .utils import copyfiles
 from .utils import loadenv
 from .utils import makedirs
+from .utils import require_command
 from .utils import rmfiles
 
 
@@ -432,6 +433,8 @@ def create_catkin_build_job(context, package, package_path, dependencies, force_
             prefix=context.package_dest_path(package)
         ))
 
+        require_command('cmake', CMAKE_EXEC)
+
         # CMake command
         stages.append(CommandStage(
             'cmake',
@@ -473,6 +476,8 @@ def create_catkin_build_job(context, package, package_path, dependencies, force_
             cwd=build_space,
         ))
 
+    require_command('make', MAKE_EXEC)
+
     # Make command
     stages.append(CommandStage(
         'make',

catkin_tools/jobs/cmake.py

@@ -260,6 +260,8 @@ def create_cmake_build_job(context, package, package_path, dependencies, force_c
         dest_path=os.path.join(metadata_path, 'package.xml')
     ))
 
+    require_command('cmake', CMAKE_EXEC)
+
     # CMake command
     makefile_path = os.path.join(build_space, 'Makefile')
     if not os.path.isfile(makefile_path) or force_cmake:
@@ -291,6 +293,8 @@ def create_cmake_build_job(context, package, package_path, dependencies, force_c
             cwd=build_space,
         ))
 
+    require_command('make', MAKE_EXEC)
+
     # Make command
     stages.append(CommandStage(
         'make',

catkin_tools/jobs/utils.py

@@ -25,6 +25,20 @@
 from catkin_tools.execution.events import ExecutionEvent
 
 
+class CommandMissing(Exception):
+    '''A required command is missing.'''
+
+    def __init__(self, name):
+        super(CommandMissing, self).__init__(
+                'Cannot find required tool `%s` on the PATH, is it installed?' % name)
+
+
+def require_command(name, which):
+    if not which:
+        import errno
+        raise CommandMissing(name)
+
+
 def get_env_loaders(package, context):
     """Get a list of env loaders required to build this package."""
 

catkin_tools/verbs/catkin_build/build.py

@@ -57,6 +57,7 @@
 from catkin_tools.jobs.catkin import create_catkin_build_job
 from catkin_tools.jobs.catkin import create_catkin_clean_job
 from catkin_tools.jobs.catkin import get_prebuild_package
+from catkin_tools.jobs.utils import CommandMissing
 
 from .color import clr
 
@@ -461,49 +462,53 @@ def build_isolated_workspace(
     if len(build_job_creators) == 0:
         sys.exit('Error: No build types available. Please check your catkin_tools installation.')
 
-    # Construct jobs
-    for pkg_path, pkg in all_packages:
-        if pkg.name not in packages_to_be_built_names:
-            continue
+    try:
+        # Construct jobs
+        for pkg_path, pkg in all_packages:
+            if pkg.name not in packages_to_be_built_names:
+                continue
+
+            # Ignore metapackages
+            if 'metapackage' in [e.tagname for e in pkg.exports]:
+                continue
+
+            # Get actual execution deps
+            deps = [
+                p.name for _, p
+                in get_cached_recursive_build_depends_in_workspace(pkg, packages_to_be_built)
+                if p.name not in prebuild_jobs
+            ]
+            # All jobs depend on the prebuild jobs if they're defined
+            if not no_deps:
+                for j in prebuild_jobs.values():
+                    deps.append(j.jid)
+
+            # Determine the job parameters
+            build_job_kwargs = dict(
+                context=context,
+                package=pkg,
+                package_path=pkg_path,
+                dependencies=deps,
+                force_cmake=force_cmake,
+                pre_clean=pre_clean)
 
-        # Ignore metapackages
-        if 'metapackage' in [e.tagname for e in pkg.exports]:
-            continue
+            # Create the job based on the build type
+            build_type = get_build_type(pkg)
 
-        # Get actual execution deps
-        deps = [
-            p.name for _, p
-            in get_cached_recursive_build_depends_in_workspace(pkg, packages_to_be_built)
-            if p.name not in prebuild_jobs
-        ]
-        # All jobs depend on the prebuild jobs if they're defined
-        if not no_deps:
-            for j in prebuild_jobs.values():
-                deps.append(j.jid)
-
-        # Determine the job parameters
-        build_job_kwargs = dict(
-            context=context,
-            package=pkg,
-            package_path=pkg_path,
-            dependencies=deps,
-            force_cmake=force_cmake,
-            pre_clean=pre_clean)
-
-        # Create the job based on the build type
-        build_type = get_build_type(pkg)
-
-        if build_type in build_job_creators:
-            jobs.append(build_job_creators[build_type](**build_job_kwargs))
-        else:
-            wide_log(clr(
-                "[build] @!@{yf}Warning:@| Skipping package `{}` because it "
-                "has an unsupported package build type: `{}`"
-            ).format(pkg.name, build_type))
-
-            wide_log(clr("[build] Note: Available build types:"))
-            for bt_name in build_job_creators.keys():
-                wide_log(clr("[build]  - `{}`".format(bt_name)))
+            if build_type in build_job_creators:
+                jobs.append(build_job_creators[build_type](**build_job_kwargs))
+            else:
+                wide_log(clr(
+                    "[build] @!@{yf}Warning:@| Skipping package `{}` because it "
+                    "has an unsupported package build type: `{}`"
+                ).format(pkg.name, build_type))
+
+                wide_log(clr("[build] Note: Available build types:"))
+                for bt_name in build_job_creators.keys():
+                    wide_log(clr("[build]  - `{}`".format(bt_name)))
+
+    except CommandMissing as e:
+        sys.exit(clr("[build] @!@{rf}Error:@| {0}").format(e))
 
     # Queue for communicating status
     event_queue = Queue()