I currently have an nginx/1.28.1 reverse proxy running on my server.
server {
listen 443 ssl http2;
listen [::]:443 ssl http2;
listen 443 quic reuseport;
listen [::]:443 quic reuseport;
server_name minio.s3.com;
ssl_protocols TLSv1.2 TLSv1.3;
http3 on;
add_header Alt-Svc 'h3=":443"; ma=86400' always;
ssl_certificate /etc/nginx/certs/fullchain.pem;
ssl_certificate_key /etc/nginx/certs/privkey.pem;
location / {
# Points at random port
proxy_pass http://localhost:1234;
}
}I make a get request to this using the reqwest client below (version 0.13.1 with http3 feature) and get an error:
#[tokio::main]
async fn main() -> Result<(), reqwest::Error> {
let client = reqwest::Client::builder()
.tls_danger_accept_invalid_certs(true)
.http3_prior_knowledge()
.build()?;
let res = client
.get("https://server:443/")
.version(http::Version::HTTP_3)
.send()
.await?;
eprintln!("Response: {:?} {}", res.version(), res.status());
eprintln!("Headers: {:#?}\n", res.headers());
let body = res.text().await?;
println!("{body}");
Ok(())
}$ cargo run
Error: reqwest::Error { kind: Request, url: "https://server:443/",
source: reqwest::Error { kind: Request, source: RemoteTerminate { code: H3_INTERNAL_ERROR } } }However, by turning grease off, the request works properly:
let client = reqwest::Client::builder()
.tls_danger_accept_invalid_certs(true)
.http3_prior_knowledge()
.http3_send_grease(false) // Disable grease
.build()?;$ cargo run
Response: HTTP/3.0 502 Bad Gateway
Headers: {
"server": "nginx/1.28.1",
"date": "Sun, 01 Mar 2026 23:26:11 GMT",
"content-type": "text/html",
"content-length": "157",
"alt-svc": "h3=\":443\"; ma=86400",
}
<html>
<head><title>502 Bad Gateway</title></head>
<body>
<center><h1>502 Bad Gateway</h1></center>
<hr><center>nginx/1.28.1</center>
</body>
</html>Not sure why this happens, but it would be nice to point this out in case people decide to test reqwest with an nginx server.
I currently have an
nginx/1.28.1reverse proxy running on my server.I make a get request to this using the reqwest client below (version 0.13.1 with http3 feature) and get an error:
$ cargo run Error: reqwest::Error { kind: Request, url: "https://server:443/", source: reqwest::Error { kind: Request, source: RemoteTerminate { code: H3_INTERNAL_ERROR } } }However, by turning grease off, the request works properly:
$ cargo run Response: HTTP/3.0 502 Bad Gateway Headers: { "server": "nginx/1.28.1", "date": "Sun, 01 Mar 2026 23:26:11 GMT", "content-type": "text/html", "content-length": "157", "alt-svc": "h3=\":443\"; ma=86400", } <html> <head><title>502 Bad Gateway</title></head> <body> <center><h1>502 Bad Gateway</h1></center> <hr><center>nginx/1.28.1</center> </body> </html>Not sure why this happens, but it would be nice to point this out in case people decide to test reqwest with an nginx server.