curl no longer able to access localhost running Go server

[vkuznet (Valentin Kuznetsov)]

After recent update of curl I found that it can't access my localhost host running Go server. The output I see is the following:

*   Trying 127.0.0.1:8989...
* Connected to localhost (127.0.0.1) port 8989 (#0)
> GET /api HTTP/1.1
> Host: localhost:8989
> User-Agent: curl/7.78.0
> Accept: */*
>

After that it hangs forever. I don't see that request arrive to my server. If I use system curl then everything is fine, e.g.

*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8989 (#0)
> GET /api HTTP/1.1
> Host: localhost:8989
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
...

I noticed it recently after upgrade of my ports, and previous versions of curl were working just fine.

The difference between macports curl and system one is the following:

/opt/local/bin/curl -V
curl 7.78.0 (x86_64-apple-darwin20.6.0) libcurl/7.78.0 OpenSSL/1.1.1l zlib/1.2.11 zstd/1.5.0 libidn2/2.3.2 libpsl/0.21.1 (+libidn2/2.3.2)
Release-Date: 2021-07-21
Protocols: dict file ftp ftps gopher gophers http https imap imaps mqtt pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: alt-svc AsynchDNS HSTS HTTPS-proxy IDN IPv6 Largefile libz NTLM NTLM_WB PSL SSL TLS-SRP UnixSockets zstd

and system curl

/usr/bin/curl -V
curl 7.64.1 (x86_64-apple-darwin20.0) libcurl/7.64.1 (SecureTransport) LibreSSL/2.8.3 zlib/1.2.11 nghttp2/1.41.0
Release-Date: 2019-03-27
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: AsynchDNS GSS-API HTTP2 HTTPS-proxy IPv6 Kerberos Largefile libz MultiSSL NTLM NTLM_WB SPNEGO SSL UnixSockets

Said that, I can access remote sites just fine using either version of curl tool

Thanks, Valentin.

[ryandesign (Ryan Carsten Schmidt)]

I will assign the ticket to myself since I maintain the curl port but I have no idea what to suggest to resolve this issue, other than that you contact the developers of curl or a curl support venue.

[vkuznet (Valentin Kuznetsov)]

I filed the curl ticket here: ​https://github.com/curl/curl/issues/7906

[vkuznet (Valentin Kuznetsov)]

Hi, I want to update on this issue. Turns out it was collision of port usage between my app and one of the apps on my system. We resolved the issue in curl ticket and therefore it is no longer required to change anything here. Please close the issue.

[ryandesign (Ryan Carsten Schmidt)]

Great, glad you got it figured out.