Resolve TypeError during FuzzContext creation

[AashutoshMurthy]

This PR aims to resolve the following error:
TypeError: bad argument type for built-in operation

The value of fuzzer_metadata for the key 'issue_metadata' is a dict, it should be a str.

[svasudevprasad]

/gcbrun

[jonathanmetzman]

I think this needs more thought. We are returning a dict elsewhere, do all users of this need a string? Why bother loading it.

[AashutoshMurthy]

I think this needs more thought. We are returning a dict elsewhere, do all users of this need a string? Why bother loading it.

I had a look at the usage of issue_metadata, and have summarised my findings in the chart below:

From this, I feel we can probably change the fix to convert issue_metadata from a dict to str in fuzz_task.py, as the same logic has been implemented elsewhere. Here's the reference where issue_metadata is converted to a str using json.dumps() wherever needed.

[jonathanmetzman]

I think this needs more thought. We are returning a dict elsewhere, do all users of this need a string? Why bother loading it.

I had a look at the usage of issue_metadata, and have summarised my findings in the chart below:

From this, I feel we can probably change the fix to convert issue_metadata from a dict to str in fuzz_task.py, as the same logic has been implemented elsewhere. Here's the reference where issue_metadata is converted to a str using json.dumps() wherever needed.

Sure, let's do that.