Stop variable shadowing from breaking dynamic tags

[avdgaag]

Summary

Fix dynamic tags being evaluated only once.

Description

Re-assigning the tags variable defined outside a block inside the block overrides that value for subsequent calls. That caused dynamic tags to be evaluated once and then be fixed to that first value — rather than being dynamically evaluated on every invocation. By using a unique variable name, this is prevented from happening.

Example

See the added tests; they fail without the change in this PR.

[casperisfine]

@avdgaag thanks for the fix. However, sorry but could you sign the CLA thing? :/

[avdgaag]

I have signed the CLA!

[casperisfine]

Thank you!