Files
jak-project/third-party/curl/docs/cmdline-opts/variable.md
T
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

3.4 KiB
Vendored
Generated

c, SPDX-License-Identifier, Long, Arg, Help, Category, Added, Multi, See-also, Example
c SPDX-License-Identifier Long Arg Help Category Added Multi See-also Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl variable <[%]name=text/@file> Set variable curl 8.3.0 append
config
--variable name=smith --expand-url "$URL/{{name}}"

--variable

Set a variable with name=content or name@file (where file can be stdin if set to a single dash (-)). The name is a case sensitive identifier that must consist of no other letters than a-z, A-Z, 0-9 or underscore. The specified content is then associated with this identifier.

Setting the same variable name again overwrites the old contents with the new.

The contents of a variable can be referenced in a later command line option when that option name is prefixed with --expand-, and the name is used as {{name}}.

--variable can import environment variables into the name space. Opt to either require the environment variable to be set or provide a default value for the variable in case it is not already set.

--variable %name imports the variable called name but exits with an error if that environment variable is not already set. To provide a default value if the environment variable is not set, use --variable %name=content or --variable %name@content. Note that on some systems - but not all - environment variables are case insensitive.

Added in curl 8.12.0: you can get a byte range from the source by appending [start-end] to the variable name, where start and end are byte offsets to include from the contents. For example, asking for offset "2-10" means offset two to offset ten, inclusive, resulting in 9 bytes in total. 2-2 means a single byte at offset 2. Not providing a second number implies to the end of data. The start offset cannot be larger than the end offset. Asking for a range that is outside of the file size makes the variable contents empty. For example, getting the first one hundred bytes from a given file:

curl --variable "fraction[0-99]@filename"

Given a byte range that has no data results in an empty string. Asking for a range that is larger than the content makes curl use the piece of the data that exists.

To assign a variable using contents from another variable, use --expand-variable. Like for example assigning a new variable using contents from two other:

curl --expand-variable "user={{firstname}} {{lastname}}"

When expanding variables, curl supports a set of functions that can make the variable contents more convenient to use. You apply a function to a variable expansion by adding a colon and then list the desired functions in a comma-separated list that is evaluated in a left-to-right order. Variable content holding null bytes that are not encoded when expanded causes an error.

Available functions:

trim

removes all leading and trailing white space.

Example:

curl --expand-url https://example.com/{{var:trim}}

json

outputs the content using JSON string quoting rules.

Example:

curl --expand-data {{data:json}} https://example.com

url

shows the content URL (percent) encoded.

Example:

curl --expand-url https://example.com/{{path:url}}

b64

expands the variable base64 encoded

Example:

curl --expand-url https://example.com/{{var:b64}}

64dec

decodes a base64 encoded character sequence. If the sequence is not possible to decode, it instead outputs [64dec-fail]

Example:

curl --expand-url https://example.com/{{var:64dec}}

(Added in 8.13.0)