fix: Lock SNS version

src/dfx/src/commands/nns/import.rs

@@ -24,7 +24,7 @@ pub async fn exec(env: &dyn Environment, opts: ImportOpts) -> DfxResult {
     let mut config = config.as_ref().clone();
 
     let network_mappings = get_network_mappings(&opts.network_mapping)?;
-    let ic_commit = replica_rev();
+    let ic_commit = std::env::var("DFX_IC_REF").unwrap_or_else(|_| replica_rev().to_string());
 
     let dfx_url_str = {
         let ic_project = std::env::var("DFX_IC_SRC").unwrap_or_else(|_| {

src/dfx/src/commands/sns/import.rs

@@ -1,4 +1,5 @@
 use crate::lib::error::DfxResult;
+use crate::lib::info::replica_rev;
 use crate::lib::project::import::import_canister_definitions;
 use crate::lib::project::network_mappings::get_network_mappings;
 use crate::Environment;
@@ -26,10 +27,13 @@ pub fn exec(env: &dyn Environment, opts: SnsImportOpts) -> DfxResult {
     let network_mappings = get_network_mappings(&opts.network_mapping)?;
 
     let runtime = Runtime::new().expect("Unable to create a runtime");
+    let ic_commit = std::env::var("DFX_IC_REF").unwrap_or_else(|_| replica_rev().to_string());
+    let their_dfx_json_location =
+        format!("https://raw.githubusercontent.com/dfinity/ic/{ic_commit}/rs/sns/cli/dfx.json");
     runtime.block_on(import_canister_definitions(
         env.get_logger(),
         &mut config,
-        "https://raw.githubusercontent.com/dfinity/ic/master/rs/sns/cli/dfx.json",
+        &their_dfx_json_location,
         None,
         None,
         &network_mappings,

src/dfx/src/lib/nns/install_nns.rs

@@ -179,6 +179,9 @@ async fn get_subnet_id(agent: &Agent) -> anyhow::Result<Principal> {
 /// The NNS canisters use the very first few canister IDs; they must be available.
 #[context("Failed to verify that the network is empty; dfx nns install must be run just after dfx start --clean")]
 async fn verify_nns_canister_ids_are_available(agent: &Agent) -> anyhow::Result<()> {
+    /// Checks that the canister is unused on the given network.
+    ///
+    /// The network is queried directly; local state such as canister_ids.json has no effect on this function.
     async fn verify_canister_id_is_available(
         agent: &Agent,
         canister_id: &str,
@@ -415,24 +418,24 @@ pub async fn download_ic_repo_wasm(
 /// Downloads all the core NNS wasms, excluding only the front-end wasms II and NNS-dapp.
 #[context("Failed to download NNS wasm files.")]
 pub async fn download_nns_wasms(env: &dyn Environment) -> anyhow::Result<()> {
-    let ic_commit = replica_rev();
+    let ic_commit = std::env::var("DFX_IC_REF").unwrap_or_else(|_| replica_rev().to_string());
     let wasm_dir = &nns_wasm_dir(env);
     for IcNnsInitCanister {
         wasm_name,
         test_wasm_name,
         ..
     } in NNS_CORE
     {
-        download_ic_repo_wasm(wasm_name, ic_commit, wasm_dir).await?;
+        download_ic_repo_wasm(wasm_name, &ic_commit, wasm_dir).await?;
         if let Some(test_wasm_name) = test_wasm_name {
-            download_ic_repo_wasm(test_wasm_name, ic_commit, wasm_dir).await?;
+            download_ic_repo_wasm(test_wasm_name, &ic_commit, wasm_dir).await?;
         }
     }
     try_join_all(
         SNS_CANISTERS
             .iter()
             .map(|SnsCanisterInstallation { wasm_name, .. }| {
-                download_ic_repo_wasm(wasm_name, ic_commit, wasm_dir)
+                download_ic_repo_wasm(wasm_name, &ic_commit, wasm_dir)
             }),
     )
     .await?;