use_warbler seems to do nothing

[groma84]

Setting use_warbler in a pipeline seems to do nothing. E.g. creating a view showing the current time is run once at the start of the program and is then never evaluated again. Using the warbler function explictly works.

I made a small repro in this repo: https://github.com/groma84/saturn-warbler-repro

Running the program and opening http://localhost:5000/works gets the current time. But opening http://localhost:5000/broken shows the time from the program start, although the pipeline has use_warbler in it.

I tried fixing it already in Saturn but sadly failed.