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Alexander J. Semenuk 5d5e35fb9b fix: Windows toolchain compatibility (curl 8.21 re-vendor, endless reconfigure loop) (#4355)
## Problem

Windows builds break with a current local toolchain (Scoop LLVM 22.1.8,
CMake 4.4.0, VS 2026), in two independent ways:

1. The build stops at curl's deliberate guard: `#error "no non-blocking
method was found/used/set"` in `third-party/curl/lib/nonblock.c`.
2. From the second configure onward, `cmake --build` re-runs CMake in an
endless loop (observed 42 consecutive reconfigure cycles in a single
build). Likely the same mechanism behind the "endlessly building" VS
2026 note in `docs/setup/dev/vs.md`.

## Root cause

1. `third-party/curl/CMake/CurlTests.c` passes `int *` to
`ioctlsocket()`, whose third parameter is `u_long *`. Clang 22 promotes
`-Wincompatible-pointer-types` to a hard error in C, so the
`HAVE_IOCTLSOCKET_FIONBIO` try_compile silently fails and
`curl_config.h` never defines it. Upstream CI does not see this because
the windows-2022 runner image ships an older LLVM. GCC 14 promotes the
same warning to a hard error, which is very likely the `CurlTests.c.obj`
failure reported from MSYS2 in open-goal/jak-project#3551. Upstream curl
hit the identical problem with GCC 14 and fixed the probe in curl 8.8.0
(curl/curl#13578).
2. The root CMakeLists copies the build tree's `compile_commands.json`
into `<src>/build/` for clangd using `configure_file()`, which registers
its input as a configure dependency. CMake rewrites
`compile_commands.json` late in every generation, after
`CTestTestfile.cmake` and `cmake_install.cmake` (outputs of the same
Ninja regen rule), so once the dependency is registered the rule is
deterministically dirty and every `ninja` invocation re-runs CMake. A
pristine first configure is safe (the file does not exist yet, so the
`if(EXISTS ...)` guard skips the copy), which is why the loop looks
machine- or IDE-specific.

## Fix

1. Per review, re-vendor `third-party/curl` at the `curl-8_21_0` tag
(previously `curl-8_3_0`), which carries the upstream probe fix plus two
years of upstream development; `vendor.yaml` updated to match.
Adjustments the version jump forced:
- curl 8.15 removed the native macOS Secure Transport backend
(`CURL_USE_SECTRANSP`), so macOS now builds curl against OpenSSL like
Linux. The two macOS workflows install Homebrew `openssl@3` and export
`OPENSSL_ROOT_DIR` (keg-only), and the macOS setup docs gained the same
two lines.
- `CURL_BROTLI` / `CURL_ZSTD` switched to AUTO-detection in curl 8.10;
pinned OFF to keep the previous no-compression behavior and avoid
silently linking whatever the CI images happen to have.
- curl's new top-level `BUILD_EXAMPLES` cache option (default ON) leaked
into discord-rpc's identically named option and broke configure at a
nonexistent `examples/send-presence` directory; pinned OFF ahead of the
third-party subdirectories.

The diff is dominated by the mechanical tag-tree swap under
`third-party/curl` (linguist-vendored, collapsed in review). The
hand-written changes are `CMakeLists.txt`, the two macOS workflows,
`docs/setup/system/macos.md`, and `vendor.yaml`.
2. Swap `configure_file()` for `file(COPY ...)`: the same clangd copy
with no configure dependency registered. (`file(COPY_FILE ...
ONLY_IF_DIFFERENT)` would be cleaner still but requires CMake 3.21,
above the declared `cmake_minimum_required(VERSION 3.10)`.)

## Test plan

- [x] Fresh `cmake --preset Release-windows-clang` (LLVM 22, no cache
seeding) completes and logs `Enabled SSL backends: Schannel`; the
FIONBIO probe passes without the previous `#error`
- [x] Full Windows Release build from scratch in the branch worktree
(all 1422 targets)
- [x] goalc-test suite: 1509 passed, 0 failed
- [x] Second consecutive configure with `compile_commands.json` present:
the regen rule in `build.ninja` has no `compile_commands.json` input;
`<src>/build/compile_commands.json` is still refreshed for clangd
- [x] Repeated `ninja` invocations after a full build no longer re-run
CMake
- [x] macOS Intel and ARM CI green (first exercise of the OpenSSL
backend switch)

---

I work off a self-hosted forge, so this GitHub account is quiet; the
configure logs and ninja dirty-node traces from the investigation are
available if anyone wants the raw data.

(AI-assisted)
2026-07-27 19:19:18 -04:00

4.5 KiB
Vendored
Generated

c, SPDX-License-Identifier, Title, Section, Source, See-also, Protocol, Added-in
c SPDX-License-Identifier Title Section Source See-also Protocol Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_RTSP_REQUEST 3 libcurl
CURLOPT_RTSP_SESSION_ID (3)
CURLOPT_RTSP_STREAM_URI (3)
RTSP
7.20.0

NAME

CURLOPT_RTSP_REQUEST - RTSP request

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RTSP_REQUEST, long request);

DESCRIPTION

Tell libcurl what kind of RTSP request to make. Pass one of the following RTSP enum values as a long in the request argument. Unless noted otherwise, commands require the Session ID to be initialized.

CURL_RTSPREQ_OPTIONS

Used to retrieve the available methods of the server. The application is responsible for parsing and obeying the response. The session ID is not needed for this method.

CURL_RTSPREQ_DESCRIBE

Used to get the low level description of a stream. The application should note what formats it understands in the 'Accept:' header. Unless set manually, libcurl automatically adds in 'Accept: application/sdp'. Time-condition headers are added to Describe requests if the CURLOPT_TIMECONDITION(3) option is used. (The session ID is not needed for this method)

CURL_RTSPREQ_ANNOUNCE

When sent by a client, this method changes the description of the session. For example, if a client is using the server to record a meeting, the client can use Announce to inform the server of all the meta-information about the session. ANNOUNCE acts like an HTTP PUT or POST like CURL_RTSPREQ_SET_PARAMETER

CURL_RTSPREQ_SETUP

Setup is used to initialize the transport layer for the session. The application must set the desired Transport options for a session by using the CURLOPT_RTSP_TRANSPORT(3) option prior to calling setup. If no session ID is currently set with CURLOPT_RTSP_SESSION_ID(3), libcurl extracts and uses the session ID in the response to this request. The session ID is not needed for this method.

CURL_RTSPREQ_PLAY

Send a Play command to the server. Use the CURLOPT_RANGE(3) option to modify the playback time (e.g. npt=10-15).

CURL_RTSPREQ_PAUSE

Send a Pause command to the server. Use the CURLOPT_RANGE(3) option with a single value to indicate when the stream should be halted. (e.g. npt=25)

CURL_RTSPREQ_TEARDOWN

This command terminates an RTSP session. Closing a connection does not terminate the RTSP session since it is valid to control an RTSP session over different connections.

CURL_RTSPREQ_GET_PARAMETER

Retrieve a parameter from the server. By default, libcurl adds a Content-Type: text/parameters header on all non-empty requests unless a custom one is set. GET_PARAMETER acts like an HTTP PUT or POST (see CURL_RTSPREQ_SET_PARAMETER). Applications wishing to send a heartbeat message (e.g. in the presence of a server-specified timeout) should send use an empty GET_PARAMETER request.

CURL_RTSPREQ_SET_PARAMETER

Set a parameter on the server. By default, libcurl uses a Content-Type: text/parameters header unless a custom one is set. The interaction with SET_PARAMETER is much like an HTTP PUT or POST. An application may either use CURLOPT_UPLOAD(3) with CURLOPT_READDATA(3) like an HTTP PUT, or it may use CURLOPT_POSTFIELDS(3) like an HTTP POST. No chunked transfers are allowed, so the application must set the CURLOPT_INFILESIZE(3) in the former and CURLOPT_POSTFIELDSIZE(3) in the latter. Also, there is no use of multi-part POSTs within RTSP.

CURL_RTSPREQ_RECORD

Used to tell the server to record a session. Use the CURLOPT_RANGE(3) option to modify the record time.

CURL_RTSPREQ_RECEIVE

This is a special request because it does not send any data to the server. The application may call this function in order to receive interleaved RTP data. It returns after processing one read buffer of data in order to give the application a chance to run.

DEFAULT

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "rtsp://example.com/");
    /* ask for options */
    curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_OPTIONS);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

HISTORY

CURL_RTSPREQ_* enums became long types in 8.13.0, prior to this version a long cast was necessary when passed to curl_easy_setopt(3).

%AVAILABILITY%

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).