fs.lua: fix error message when source file is missing

Fixes #1147.

1 files changed, 3 insertions, 1 deletions

diff --git a/spec/fs_spec.lua b/spec/fs_spec.lua
index 5d8926c4..16295869 100644
--- a/spec/fs_spec.lua
+++ b/spec/fs_spec.lua
@@ -894,7 +894,9 @@ describe("Luarocks fs test #unit", function()
       it("returns false and does nothing if the source file does not exist", function()
          srcfile = get_tmp_path()
          dstfile = get_tmp_path()
-         assert.falsy(fs.copy(srcfile, dstfile, nil))
+         local ok, err = fs.copy(srcfile, dstfile, nil)
+         assert.falsy(ok)
+         assert.not_match("are the same file", err)
          assert.falsy(exists_file(dstfile))
       end)