SoyFileSet.extractMsgs - error in one template truncates message bundle

Reproduction: Create a SoyFileSet containing two files: a valid file with a message and one that lacks a namespace declaration

Example file content:

foo.soy

``` soy
{namespace foo}

/** */
{template .test}
{msg desc=""}Test msg{/msg}
{/template}
```

invalid.soy

``` soy
/** */
{template .test}
invalid due to missing namespace
{/template}
```

If the valid file is added first, extractMsgs() will return its message. If the invalid soy is added first, then the bundle will not contain the message. In that case, SoyFileSet.generateTemplateRegistry also excludes the second file's template, and SoyFileSet.compileToTofu throws an exception (as expected).

I presume that extractMsgs does not compile the templates / throw an exception so that the process that extracts messages does not need to have the same configuration (globals, file set, etc) as the real application. But I would expect that an unrecoverable error in one file would not silently truncate the resulting bundle.

We caught this only because we have an alert when the number of translations drops by 10% or more, but I'm not sure how to prevent it from happening in the future other than developer education.

Thoughts?

Thank you,
Rob