From 3fbc5eeb11e6b9abf66e38ab32d85a2edf9f76e1 Mon Sep 17 00:00:00 2001
From: Zhaofeng Li <hello@zhaofeng.li>
Date: Wed, 17 Aug 2022 11:56:30 -0600
Subject: [PATCH] repl: Add arguments depending on Nix version

---
 src/command/repl.rs | 23 +++++++++++++++++------
 src/nix/info.rs     | 10 +++++++++-
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/command/repl.rs b/src/command/repl.rs
index b2c5436..a642367 100644
--- a/src/command/repl.rs
+++ b/src/command/repl.rs
@@ -5,6 +5,7 @@ use tempfile::Builder as TempFileBuilder;
 use tokio::process::Command;
 
 use crate::error::ColmenaError;
+use crate::nix::info::NixCheck;
 use crate::util;
 
 pub fn subcommand() -> ClapCommand<'static> {
@@ -20,6 +21,9 @@ attribute set."#,
 }
 
 pub async fn run(_global_args: &ArgMatches, local_args: &ArgMatches) -> Result<(), ColmenaError> {
+    let nix_check = NixCheck::detect().await;
+    let nix_version = nix_check.version().expect("Could not detect Nix version");
+
     let hive = util::hive_from_args(local_args).await?;
 
     let expr = hive.get_repl_expression();
@@ -31,14 +35,21 @@ pub async fn run(_global_args: &ArgMatches, local_args: &ArgMatches) -> Result<(
 
     expr_file.write_all(expr.as_bytes())?;
 
-    let status = Command::new("nix")
-        .arg("repl")
+    let mut repl_cmd = Command::new("nix");
+
+    repl_cmd.arg("repl");
+
+    if nix_version.at_least(2, 4) {
         // `nix repl` is expected to be marked as experimental:
         // <https://github.com/NixOS/nix/issues/5604>
-        .args(&["--experimental-features", "nix-command flakes"])
-        .arg(expr_file.path())
-        .status()
-        .await?;
+        repl_cmd.args(&["--experimental-features", "nix-command flakes"]);
+    }
+
+    if nix_version.at_least(2, 10) {
+        repl_cmd.arg("--file");
+    }
+
+    let status = repl_cmd.arg(expr_file.path()).status().await?;
 
     if !status.success() {
         return Err(status.into());
diff --git a/src/nix/info.rs b/src/nix/info.rs
index 906e658..16f4ccd 100644
--- a/src/nix/info.rs
+++ b/src/nix/info.rs
@@ -7,7 +7,7 @@ use tokio::process::Command;
 
 use super::{ColmenaError, ColmenaResult};
 
-struct NixVersion {
+pub struct NixVersion {
     major: usize,
     minor: usize,
     string: String,
@@ -37,6 +37,10 @@ impl NixVersion {
     fn has_flakes(&self) -> bool {
         self.major > 2 || (self.major == 2 && self.minor >= 4)
     }
+
+    pub fn at_least(&self, major: usize, minor: usize) -> bool {
+        self.major >= major && self.minor >= minor
+    }
 }
 
 impl fmt::Display for NixVersion {
@@ -147,4 +151,8 @@ impl NixCheck {
     pub fn flakes_supported(&self) -> bool {
         self.flakes_supported
     }
+
+    pub fn version(&self) -> Option<&NixVersion> {
+        self.version.as_ref()
+    }
 }