fix: installing pr-releases

Author: Kha

CHANGELOG.md

@@ -1,3 +1,7 @@
+# Unreleased
+
+- Fix installing from `leanprover/lean4-pr-releases`, which are not part of release.lean-lang.org.
+
 # 4.1.0 - 2025-04-30
 
 - Fetch releases and assets from release.lean-lang.org instead of parsing GitHub HTML. Makes

src/elan-dist/src/manifestation.rs

@@ -13,7 +13,15 @@ use elan_utils::{raw::read_file, utils};
 use fslock::LockFile;
 
 pub const DEFAULT_ORIGIN: &str = "leanprover/lean4";
-pub const DEFAULT_ORIGIN_JSON_URL: &str = "https://release.lean-lang.org";
+const DEFAULT_ORIGIN_JSON_URL: &str = "https://release.lean-lang.org";
+
+pub fn get_json_uri_for_releases(origin: &str) -> Option<&str> {
+    if origin == DEFAULT_ORIGIN || origin == DEFAULT_ORIGIN.to_owned() + "-nightly" {
+        Some(DEFAULT_ORIGIN_JSON_URL)
+    } else {
+        None
+    }
+}
 
 #[derive(Debug)]
 pub struct Manifestation {
@@ -92,8 +100,7 @@ impl Manifestation {
         // For historical reasons, the informal target for Linux x64 is a substring of Linux
         // aarch64; make sure we don't confuse them
         let name_substring = informal_target.clone() + ".";
-        let url = if origin.starts_with(DEFAULT_ORIGIN) {
-            let url = DEFAULT_ORIGIN_JSON_URL;
+        let url = if let Some(url) = get_json_uri_for_releases(origin) {
             let json = fetch_url(url)?;
             let releases = json::parse(&json)
                 .chain_err(|| format!("failed to parse release data: {}", url))?;

src/elan/toolchain.rs

@@ -6,8 +6,8 @@ use crate::notifications::*;
 use elan_dist::dist::ToolchainDesc;
 use elan_dist::download::DownloadCfg;
 use elan_dist::manifest::Component;
+use elan_dist::manifestation::get_json_uri_for_releases;
 use elan_dist::manifestation::DEFAULT_ORIGIN;
-use elan_dist::manifestation::DEFAULT_ORIGIN_JSON_URL;
 use elan_utils::utils;
 use elan_utils::utils::fetch_url;
 use itertools::Itertools;
@@ -136,8 +136,8 @@ pub fn resolve_toolchain_desc_ext(
                 use_cache,
             )
         } else if release == "stable" || release == "beta" || release == "nightly" {
-            let fetch = if origin.starts_with(DEFAULT_ORIGIN) {
-                utils::fetch_latest_release_json(DEFAULT_ORIGIN_JSON_URL, release, no_net)
+            let fetch = if let Some(uri) = get_json_uri_for_releases(origin) {
+                utils::fetch_latest_release_json(uri, release, no_net)
             } else {
                 if release == "beta" {
                     return Err(Error::from(