jdx · jdx · Jun 17, 2026 · Jun 15, 2026 · Jun 16, 2026 · Jun 17, 2026
diff --git a/docs/dev-tools/backends/pipx.md b/docs/dev-tools/backends/pipx.md
@@ -30,7 +30,6 @@ If you have `uv` installed, mise will use `uv tool install` under the hood and y
 mise forwards [`minimum_release_age`](/configuration/settings.html#minimum_release_age)
 to transitive Python dependency resolution during install. The uv install path uses uv's
 `--exclude-newer` flag, and the `pipx` fallback passes pip's `--uploaded-prior-to` flag.
-When using `minimum_release_age` with the `pipx` install path, `pip >= 26.0` is required for pip's `--uploaded-prior-to` support, and you are responsible for ensuring that compatible Python/pip environment is installed.
 
 In case you need `pipx` for other reasons, you can install it with or without mise.
 Here is how to install `pipx` with mise:

diff --git a/e2e/backend/test_pipx_minimum_release_age b/e2e/backend/test_pipx_minimum_release_age
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+require_cmd python3
+
+export MISE_PYTHON_COMPILE=0
+export MISE_PYTHON_GITHUB_ATTESTATIONS=0
+export MISE_PIPX_UVX=0
+
+cat >.mise.toml <<EOF
+[settings]
+minimum_release_age = "7d"
+
+[tools]
+python = "3.12"
+pipx = "1.12.0"
+"pipx:cowsay" = "latest"
+EOF
+
+mise install
+assert_succeed "mise x -- cowsay --version"
diff --git a/src/backend/pipx.rs b/src/backend/pipx.rs
@@ -293,6 +293,32 @@ impl Backend for PIPXBackend {
             }
             cmd.execute()?;
         } else {
+            // pipx forwards install `--pip-args` into shared-library bootstrap
+            // (`pip install --upgrade pip>=23.1`), not just the package install. When mise
+            // passes `--uploaded-prior-to`, bootstrap pip from ensurepip may not understand
+            // that flag (see pypa/pipx#544). Run upgrade-shared without release-age flags
+            // first so shared pip is valid; the subsequent install's shared_libs.create()
+            // then no-ops and `--uploaded-prior-to` applies only to the package install.
+            if ctx.before_date.is_some() {
+                ctx.pr.set_message("pipx upgrade-shared".to_string());
+                if let Err(err) = async {
+                    Self::pipx_cmd(
+                        &ctx.config,
+                        &["upgrade-shared"],
+                        self,
+                        &tv,
+                        &ctx.ts,
+                        ctx.pr.as_ref(),
+                    )
+                    .await?
+                    .execute()
+                }
+                .await
+                {
+                    debug!("failed to upgrade pipx shared libraries before install: {err:#}");
+                }
+            }
+
             ctx.pr.set_message(format!("pipx install {pipx_request}"));
             let mut cmd = Self::pipx_cmd(
                 &ctx.config,