change copy_file function to raise an error when trying to copy non-existing file

easybuild/tools/filetools.py

@@ -2271,7 +2271,11 @@ def copy_file(path, target_path, force_in_dry_run=False):
     :param force_in_dry_run: force copying of file during dry run
     """
     if not force_in_dry_run and build_option('extended_dry_run'):
+        # If in dry run mode, do not copy any files, just lie about it
         dry_run_msg("copied file %s to %s" % (path, target_path))
+    elif not os.path.exists(path) and not os.path.islink(path):
+        # NOTE: 'exists' will return False if 'path' is a broken symlink
+        raise EasyBuildError("Could not copy '%s' it does not exist!", path)
     else:
         try:
             target_exists = os.path.exists(target_path)
@@ -2285,13 +2289,14 @@ def copy_file(path, target_path, force_in_dry_run=False):
                 _log.info("Copied contents of file %s to %s", path, target_path)
             else:
                 mkdir(os.path.dirname(target_path), parents=True)
-                if os.path.exists(path):
-                    shutil.copy2(path, target_path)
-                elif os.path.islink(path):
+                if os.path.islink(path):
                     # special care for copying broken symlinks
                     link_target = os.readlink(path)
                     symlink(link_target, target_path)
-                _log.info("%s copied to %s", path, target_path)
+                    _log.info("created symlink from %s to %s", path, target_path)
+                else:
+                    shutil.copy2(path, target_path)
+                    _log.info("%s copied to %s", path, target_path)
         except (IOError, OSError, shutil.Error) as err:
             raise EasyBuildError("Failed to copy file %s to %s: %s", path, target_path, err)
 

test/framework/filetools.py

@@ -45,7 +45,7 @@
 from easybuild.tools import run
 import easybuild.tools.filetools as ft
 from easybuild.tools.build_log import EasyBuildError
-from easybuild.tools.config import IGNORE, ERROR
+from easybuild.tools.config import IGNORE, ERROR, update_build_option
 from easybuild.tools.multidiff import multidiff
 from easybuild.tools.py2vs3 import std_urllib
 
@@ -1663,6 +1663,20 @@ def test_copy_file(self):
         self.assertTrue(ft.read_file(to_copy) == ft.read_file(target_path))
         self.assertEqual(txt, '')
 
+        # Test that a non-existing file raises an exception
+        update_build_option('extended_dry_run', False)
+        src, target = os.path.join(self.test_prefix, 'this_file_does_not_exist'), os.path.join(self.test_prefix, 'toy')
+        self.assertErrorRegex(EasyBuildError, "Could not copy *", ft.copy_file, src, target)
+        # Test that copying a non-existing file in 'dry_run' mode does noting
+        update_build_option('extended_dry_run', True)
+        self.mock_stdout(True)
+        ft.copy_file(src, target, force_in_dry_run=False)
+        txt = self.get_stdout()
+        self.mock_stdout(False)
+        self.assertTrue(re.search("^copied file %s to %s" % (src, target), txt))
+        # However, if we add 'force_in_dry_run=True' it should throw an exception
+        self.assertErrorRegex(EasyBuildError, "Could not copy *", ft.copy_file, src, target, force_in_dry_run=True)
+
     def test_copy_files(self):
         """Test copy_files function."""
         test_ecs = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'easyconfigs', 'test_ecs')