Bun's fetch sets its own Accept-Encoding and decompresses transparently, so
upstream.body is plain while upstream.headers still says gzip. Passing both on
hands the next hop a body that contradicts its own header, and it dies with
ZlibError.
Fixed for the HTML branch and missed on the pass-through, so the page rendered
while every stylesheet, script and image beside it answered 502 — which reads
as a broken asset pipeline rather than one header on one branch.
officer
87b52d1ed6