Bug in curl Variant +http3?

[Eric Hoch]

Hey all,

for a current project I wanted to test my scripts with curl using http3. 
The curl that ships with macOS 14.5 doesn't support http3, I installed 
curl with the variant +htttp3.

The most basic command being something like

curl --http3 https://blog.cloudflare.com -I

works.

Other commands like

curl -Is -w '%header{location}' -o /dev/null 
https://github.com/SAP/macOS-icon-generator/releases/latest

don't work. I get an empty output and an exit code 43.

During the build phase for the curl +http3 variant I get this warning:
Warning: Configuration logfiles contain indications of 
-Wimplicit-function-declaration; check that features were not 
accidentally disabled:
   getpass_r: found in curl-8.8.0/config.log
   _fseeki64: found in curl-8.8.0/config.log
   IoctlSocket: found in curl-8.8.0/config.log
   ioctlsocket: found in curl-8.8.0/config.log
   memrchr: found in curl-8.8.0/config.log
   CloseSocket: found in curl-8.8.0/config.log
   closesocket: found in curl-8.8.0/config.log

Using the default macports curl +ssl variant the above command

curl -Is -w '%header{location}' -o /dev/null 
https://github.com/SAP/macOS-icon-generator/releases/latest

gives me the expected output of 
https://github.com/SAP/macOS-icon-generator/releases/tag/2.0.0

The difference for the two variants is the TLS library which is gnutls 
for http3 and OpenSSL for the default curl.

On github there is this static curl 
https://github.com/stunnel/static-curl for macOS which uses openssl, 
supports http3 and works as expected.

I found this blog entry 
https://daniel.haxx.se/blog/2024/06/10/http-3-in-curl-mid-2024/ which 
explains to me that using openssl for http3 isn't easy and the best 
choice for http3. Therefore I understand using gnutls for http3 what I 
don't understand is that curl commands using the -w option break with 
gnutls and http3. Shall I file a bug report for this?

As macOS curl doesn't support http3 I won't use http3 in my script as 
this script needs to run on macs that don't have macports or brew 
installed or download curl from the above github.

Eric