Add --python-platform riscv64-unknown-linux to various commands (#15630)

## Summary

We (and I'm sure many others) are currently doing a lot of RISC-V work
in QEMU. It is possible to significantly improve the speed of
Python-related builds by taking care of the environment setup using an
AMD64 `uv` binary (bypassing binfmt/qemu-system emulation).

Some approx numbers from local testing in riscv64 Ubuntu in QEMU:

| Resolver arch | Command | Time |
| --- | --- | --- |
| riscv64 | `pip install --upgrade --break-system-packages
--index-url=https://gitlab.com/api/v4/projects/riseproject%2Fpython%2Fwheel_builder/packages/pypi/simple
openai-harmony` | 15s |
| riscv64 | `uv pip install --upgrade --system --break-system-packages
--index-url=https://gitlab.com/api/v4/projects/riseproject%2Fpython%2Fwheel_builder/packages/pypi/simple
openai-harmony` | 5s |
| amd64 | `uv pip install --python-platform=riscv64-unknown-linux
--upgrade --system --break-system-packages
--index-url=https://gitlab.com/api/v4/projects/riseproject%2Fpython%2Fwheel_builder/packages/pypi/simple
openai-harmony` | 4s |

The numbers from some larger internal packages with deeper dependency
trees are much more pronounced - 3m6 vs 43s vs 8s, in one example.

Manylinux 2.39 is specified, as it's the first (only?) RISC-V manylinux

## Test Plan

Locally, in QEMU.

`$ docker run --platform linux/riscv64 -it ubuntu:latest`, get amd64
libc into LD_LIBRARY_PATH, tests as above

crates/uv-configuration/src/target_triple.rs

@@ -78,6 +78,11 @@ pub enum TargetTriple {
     #[serde(alias = "x8664-unknown-linux-musl")]
     X8664UnknownLinuxMusl,
 
+    /// A RISCV64 Linux target.
+    #[cfg_attr(feature = "clap", value(name = "riscv64-unknown-linux"))]
+    #[serde(rename = "riscv64-unknown-linux")]
+    Riscv64UnknownLinuxGnu,
+
     /// An `x86_64` target for the `manylinux2014` platform. Equivalent to `x86_64-manylinux_2_17`.
     #[cfg_attr(feature = "clap", value(name = "x86_64-manylinux2014"))]
     #[serde(rename = "x86_64-manylinux2014")]
@@ -273,6 +278,13 @@ impl TargetTriple {
                 },
                 Arch::Aarch64,
             ),
+            Self::Riscv64UnknownLinuxGnu => Platform::new(
+                Os::Manylinux {
+                    major: 2,
+                    minor: 39,
+                },
+                Arch::Riscv64,
+            ),
             Self::Aarch64UnknownLinuxMusl => {
                 Platform::new(Os::Musllinux { major: 1, minor: 2 }, Arch::Aarch64)
             }
@@ -483,6 +495,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "aarch64",
             Self::Aarch64UnknownLinuxMusl => "aarch64",
             Self::X8664UnknownLinuxMusl => "x86_64",
+            Self::Riscv64UnknownLinuxGnu => "riscv64",
             Self::X8664Manylinux2014 => "x86_64",
             Self::X8664Manylinux217 => "x86_64",
             Self::X8664Manylinux228 => "x86_64",
@@ -525,6 +538,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "Linux",
             Self::Aarch64UnknownLinuxMusl => "Linux",
             Self::X8664UnknownLinuxMusl => "Linux",
+            Self::Riscv64UnknownLinuxGnu => "Linux",
             Self::X8664Manylinux2014 => "Linux",
             Self::X8664Manylinux217 => "Linux",
             Self::X8664Manylinux228 => "Linux",
@@ -567,6 +581,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "",
             Self::Aarch64UnknownLinuxMusl => "",
             Self::X8664UnknownLinuxMusl => "",
+            Self::Riscv64UnknownLinuxGnu => "",
             Self::X8664Manylinux2014 => "",
             Self::X8664Manylinux217 => "",
             Self::X8664Manylinux228 => "",
@@ -612,6 +627,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "",
             Self::Aarch64UnknownLinuxMusl => "",
             Self::X8664UnknownLinuxMusl => "",
+            Self::Riscv64UnknownLinuxGnu => "",
             Self::X8664Manylinux2014 => "",
             Self::X8664Manylinux217 => "",
             Self::X8664Manylinux228 => "",
@@ -656,6 +672,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "posix",
             Self::Aarch64UnknownLinuxMusl => "posix",
             Self::X8664UnknownLinuxMusl => "posix",
+            Self::Riscv64UnknownLinuxGnu => "posix",
             Self::X8664Manylinux2014 => "posix",
             Self::X8664Manylinux217 => "posix",
             Self::X8664Manylinux228 => "posix",
@@ -698,6 +715,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => "linux",
             Self::Aarch64UnknownLinuxMusl => "linux",
             Self::X8664UnknownLinuxMusl => "linux",
+            Self::Riscv64UnknownLinuxGnu => "linux",
             Self::X8664Manylinux2014 => "linux",
             Self::X8664Manylinux217 => "linux",
             Self::X8664Manylinux228 => "linux",
@@ -740,6 +758,7 @@ impl TargetTriple {
             Self::Aarch64UnknownLinuxGnu => true,
             Self::Aarch64UnknownLinuxMusl => true,
             Self::X8664UnknownLinuxMusl => true,
+            Self::Riscv64UnknownLinuxGnu => true,
             Self::X8664Manylinux2014 => true,
             Self::X8664Manylinux217 => true,
             Self::X8664Manylinux228 => true,

docs/reference/cli.md

@@ -251,6 +251,7 @@ used.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -1243,6 +1244,7 @@ environment in the project.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -1843,6 +1845,7 @@ interpreter. Use <code>--universal</code> to display the tree for all platforms,
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -2167,6 +2170,7 @@ uv tool run [OPTIONS] [COMMAND]
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -2386,6 +2390,7 @@ uv tool install [OPTIONS] <PACKAGE>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -2596,6 +2601,7 @@ Use with <code>--all</code> to apply to all tools.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -3834,6 +3840,7 @@ by <code>--python-version</code>.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -4105,6 +4112,7 @@ be used with caution, as it can modify the system Python installation.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -4394,6 +4402,7 @@ should be used with caution, as it can modify the system Python installation.</p
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>
@@ -5023,6 +5032,7 @@ Python environment if no virtual environment is found.</p>
 <li><code>aarch64-unknown-linux-gnu</code>:  An ARM64 Linux target. Equivalent to <code>aarch64-manylinux_2_28</code></li>
 <li><code>aarch64-unknown-linux-musl</code>:  An ARM64 Linux target</li>
 <li><code>x86_64-unknown-linux-musl</code>:  An <code>x86_64</code> Linux target</li>
+<li><code>riscv64-unknown-linux</code>:  A RISCV64 Linux target</li>
 <li><code>x86_64-manylinux2014</code>:  An <code>x86_64</code> target for the <code>manylinux2014</code> platform. Equivalent to <code>x86_64-manylinux_2_17</code></li>
 <li><code>x86_64-manylinux_2_17</code>:  An <code>x86_64</code> target for the <code>manylinux_2_17</code> platform</li>
 <li><code>x86_64-manylinux_2_28</code>:  An <code>x86_64</code> target for the <code>manylinux_2_28</code> platform</li>

uv.schema.json

@@ -2291,6 +2291,11 @@
           "type": "string",
           "const": "x86_64-unknown-linux-musl"
         },
+        {
+          "description": "A RISCV64 Linux target.",
+          "type": "string",
+          "const": "riscv64-unknown-linux"
+        },
         {
           "description": "An `x86_64` target for the `manylinux2014` platform. Equivalent to `x86_64-manylinux_2_17`.",
           "type": "string",