Grafana template variables are transpiled incorrectly

[Illutax]

Suppose I have a InfluxQL query

SELECT "mean" FROM "method_timed" WHERE ("environment_name" =~ /^$environment_name$/) GROUP BY "notification_type"

Where $environment_name$ is an Grafana template variable, which is used inside an regex. Currently it is transpiled to

from(bucket: "<bucket_name>")
  |> filter(fn: (r) => r._measurement == "method_timed")
  |> filter(fn: (r) => r._field == "mean")
  |> filter(fn: (r) => r.environment_name =~ /^$environment_name$/)
  |> group(columns: ["notification_type"], mode: "by")
  |> keep(columns: ["_time", "_value", "notification_type"])
  |> sort(columns: ["_time"])

But the filter (r) => r.environment_name =~ /^$environment_name$/ is not valid.

The expected result is: (r) => r.environment_name =~ /^${environment_name:regex}$/, because a template variable should be enclosed by curly braces.

And the :regex prefix is necessary because if the template variable is set to return multiple values it is set as {foo,bar,baz} which is not regex friendly.