How to make Wireshark decompress an already decrypted HTTP2 capture?

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I'm on Linux, and have installed nghttp2.

If you're running a version of Wireshark that your distribution provides as a package, then:

• If it was built with nghttp2, installing it should have installed nghttp2 (most Linux packaging systems keep track of dependencies and install required packages). In that case, installing nghttp2 shouldn't make a difference.
• If it wasn't built with nghttp2, installing nghttp2 shouldn't make a difference.

If you're running a version of Wireshark that you built yourself, you would have to have installed nghttp2, including a developer package for nghttp2, before configuring the build and building Wireshark.

Does the "About" dialog for Wireshark say it's built with nghttp2? It would be mentioned in the "Compiled" section.

This site is preventing me from either adding a comment (looks like an old broken recaptcha) or editing the original question (edits just disappear). Trying this as a last resort.

I appreciate the clarifications.

My package is provided by my distribution and it says it's compiled with nghttp2.

I also tried the official Windows version with identical results, but I don't know where to get the external package mentioned in the wiki.