`UserInfo` endpoint lookup never returns

https://inrupt.net/userinfo でハングする GET リクエストを再現し、https://inrupt.net/.well-known/openid-configuration に記載されているエンドポイントと比較してください。UserInfo の動作を NSS と oidc-op のどちらが所有しているのかを追跡してください。完了の条件は、エンドポイントが成功レスポンスまたはエラーレスポンスのいずれかを返し、OIDC ライブラリが検証を完了できることです。

As part of the OIDC login flow, during the backchannel exchange to get the access and id token (assuming you are in the auth code flow, but that's not relevant to the issue), one can perform a check against the UserInfo endpoint of the OIDC provider to check that the sub claim of the obtained ID token matches the one of the userinfo associated to the access token.

However, in the case of NSS, a lookup at https://inrupt.net/.well-known/openid-configuration shows that the userinfo endpoint exists, but a GET to https://inrupt.net/userinfo just hangs, and never get either a success or an error response. This prevents proper functioning of some OIDC libraries, and requires to be worked around. Should this be fixed in the NSS repo, or rather at the oidc-op level ?