Use system libcurl through dlopen on Linux/BSD

.github/workflows/package.yml

@@ -87,7 +87,7 @@ jobs:
       - name: Install dependencies (Alpine)
         if: matrix.platform.type == 'container'
         run: |
-          apk add --no-cache cmake make g++ linux-headers zsh bash jq shellcheck pipx git perl-utils ca-certificates nodejs
+          apk add --no-cache cmake make g++ linux-headers zsh bash jq shellcheck pipx git perl-utils ca-certificates nodejs libcurl
           apk add --no-cache --repository https://dl-cdn.alpinelinux.org/alpine/edge/main --repository https://dl-cdn.alpinelinux.org/alpine/edge/community --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing fuse3 bindfs
 
       - name: Install pre-commit
@@ -107,7 +107,7 @@ jobs:
         run: |
           sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
           sudo apt-get update --yes
-          sudo apt-get install --yes g++-14 zsh bindfs
+          sudo apt-get install --yes g++-14 zsh bindfs libcurl4
 
       - run: cmake --version
 

.github/workflows/test.yml

@@ -83,13 +83,13 @@ jobs:
         if: runner.os == 'windows' && matrix.platform.type == 'wsl-2'
         with:
           distribution: Ubuntu-24.04
-          additional-packages: cmake build-essential gcc-14 g++-14 shellcheck pipx zsh jq bindfs nodejs
+          additional-packages: cmake build-essential gcc-14 g++-14 shellcheck pipx zsh jq bindfs nodejs libcurl4
           wsl-version: 2
 
       - name: Install dependencies (Alpine)
         if: matrix.platform.type == 'container'
         run: |
-          apk add --no-cache cmake make g++ linux-headers zsh bash jq shellcheck pipx git perl-utils ca-certificates nodejs
+          apk add --no-cache cmake make g++ linux-headers zsh bash jq shellcheck pipx git perl-utils ca-certificates nodejs libcurl
           apk add --no-cache --repository https://dl-cdn.alpinelinux.org/alpine/edge/main --repository https://dl-cdn.alpinelinux.org/alpine/edge/community --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing fuse3 bindfs
 
       - name: Install pre-commit
@@ -114,7 +114,7 @@ jobs:
         run: |
           sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
           sudo apt-get update --yes
-          sudo apt-get install --yes gcc-14 g++-14 zsh bindfs
+          sudo apt-get install --yes gcc-14 g++-14 zsh bindfs libcurl4
 
       - run: cmake --version
       - name: Configure JSON Schema

DEPENDENCIES

@@ -2,10 +2,4 @@ vendorpull https://github.com/sourcemeta/vendorpull 1dcbac42809cf87cb5b045106b86
 core https://github.com/sourcemeta/core 04e936961d1e31f6b70fa5a30e115b2f7855674a
 jsonbinpack https://github.com/sourcemeta/jsonbinpack ac8e1af733a781fc4c94a14157f80970ea569479
 blaze https://github.com/sourcemeta/blaze e73e5e1667487717b44ab351a0f46e01d507fefb
-mbedtls https://github.com/Mbed-TLS/mbedtls v3.6.6
-curl https://github.com/curl/curl curl-8_20_0
-nghttp2 https://github.com/nghttp2/nghttp2 v1.67.1
-c-ares https://github.com/c-ares/c-ares v1.34.5
-libpsl https://github.com/rockdaboot/libpsl 0.21.5
-zlib https://github.com/madler/zlib v1.3.2
 ctrf https://github.com/ctrf-io/ctrf 93ea827d951390190171d37443bff169cf47c808

Dockerfile.test.alpine

@@ -1,5 +1,5 @@
 FROM alpine:3.21
-RUN apk add --no-cache cmake make g++ linux-headers zsh bash jq perl-utils
+RUN apk add --no-cache cmake make g++ linux-headers zsh bash jq perl-utils libcurl
 WORKDIR /src
 COPY CMakeLists.txt .
 COPY DEPENDENCIES DEPENDENCIES

README.markdown

@@ -199,6 +199,17 @@ Keep in mind that it is hard to provide binaries that work across GNU/Linux
 distributions. We conservatively target Ubuntu and Alpine, but you might need
 to build from source if your distribution of choice is different.
 
+> [!NOTE]
+> On GNU/Linux (and other non-macOS, non-Windows platforms), the CLI performs
+> HTTP requests through your system's cURL library, which it loads at runtime.
+> This keeps the binaries distribution-independent and makes them respect your
+> system's TLS trust store. `libcurl` is present on most systems, but if it is
+> missing you can install it through your package manager (for example
+> `apt install libcurl4`, `dnf install libcurl`, or `apk add libcurl`). If it
+> lives in a non-standard location, point the CLI at it by setting the
+> `SOURCEMETA_JSONSCHEMA_CURL_SO` environment variable to the full path of
+> `libcurl.so.4`.
+
 To verify the GPG signature of the checksums file:
 
 ```sh