From f289bdb9d4e8432160c5dcdc037a930b2025d11b Mon Sep 17 00:00:00 2001
From: "Travis A. Everett" <travis.a.everett@gmail.com>
Date: Mon, 19 Oct 2020 11:54:21 -0500
Subject: [PATCH] discourage casual Big Sur installs

---
 scripts/install-nix-from-closure.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/scripts/install-nix-from-closure.sh b/scripts/install-nix-from-closure.sh
index 4e64f3d43..ea2e47b7f 100644
--- a/scripts/install-nix-from-closure.sh
+++ b/scripts/install-nix-from-closure.sh
@@ -27,6 +27,15 @@ if [ "$(uname -s)" = "Darwin" ]; then
     IFS='.' read macos_major macos_minor macos_patch << EOF
 $(sw_vers -productVersion)
 EOF
+    # TODO: this is a temporary speed-bump to keep people from naively installing Nix
+    # on macOS Big Sur (11.0+, 10.16+) until nixpkgs updates are ready for them.
+    # *Ideally* this is gone before next Nix release. If you're intentionally working on
+    # Nix + Big Sur, just comment out this block and be on your way :)
+    if [ "$macos_major" -gt 10 ] || { [ "$macos_major" -eq 10 ] && [ "$macos_minor" -gt 15 ]; }; then
+        echo "$0: nixpkgs isn't quite ready to support macOS $(sw_vers -productVersion) yet"
+        exit 1
+    fi
+
     if [ "$macos_major" -lt 10 ] || { [ "$macos_major" -eq 10 ] && [ "$macos_minor" -lt 12 ]; } || { [ "$macos_minor" -eq 12 ] && [ "$macos_patch" -lt 6 ]; }; then
         # patch may not be present; command substitution for simplicity
         echo "$0: macOS $(sw_vers -productVersion) is not supported, upgrade to 10.12.6 or higher"