From 43eb1094726f1b863faa6fdb8afcda5b7ebb7191 Mon Sep 17 00:00:00 2001
From: Wilfred Hughes <me@wilfred.me.uk>
Date: Wed, 18 Jun 2025 21:13:03 +0100
Subject: [PATCH] Display Flatpak status in --version

---
 src/version.rs | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/version.rs b/src/version.rs
index e96adf528..63a61c2fa 100644
--- a/src/version.rs
+++ b/src/version.rs
@@ -28,11 +28,26 @@ impl fmt::Display for VersionInfo {
             writeln!(f, "Toolchain: {}", rustc_version)?;
         }
 
+        // Users running difftastic in containers sometimes have
+        // issues with permissions reading from /tmp, which is where
+        // git writes temporary files. Display whether the environment
+        // looks like a container.
+        let container_env = if std::env::var("container").is_ok() {
+            " (probably Flatpak)"
+        } else if std::env::var("APPIMAGE").is_ok() {
+            " AppImage"
+        } else if std::env::var("SNAP").is_ok() {
+            " Snap"
+        } else {
+            ""
+        };
+
         writeln!(
             f,
-            "System:    {} {}",
+            "System:    {} {}{}",
             std::env::consts::OS,
-            std::env::consts::ARCH
+            std::env::consts::ARCH,
+            container_env
         )
     }
 }