From 3c9332283c6de81d04324f3b9f7050ce80e6d261 Mon Sep 17 00:00:00 2001
From: Ana Hobden <operator@hoverbear.org>
Date: Mon, 16 Jan 2023 09:13:18 -0800
Subject: [PATCH 1/2] Ensure we still set GITHUB_PATH

Further improve logic
---
 action.yml | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/action.yml b/action.yml
index 86c5b70..074cee5 100644
--- a/action.yml
+++ b/action.yml
@@ -76,7 +76,8 @@ inputs:
     description: The branch of `nix-installer` to use
     required: false
   reinstall:
-    description: Force a reinstall if the
+    description: Force a reinstall if an existing installation is detected
+    required: false
 
 runs:
   using: composite
@@ -84,18 +85,27 @@ runs:
     - name: Install Nix
       shell: bash
       run: |
-        if [ -f "/nix/receipt.json" ]; then
-          if [ -n "${{ inputs.reinstall }}" ]; then
+        if [ -f "/nix/receipt.json" ] && [ -f "/nix/nix-installer" ]; then
+          if ([ -n "${{ inputs.nix-installer-revision }}" ] || [ -n "${{ inputs.nix-installer-branch }}" ]) && [ "${{ inputs.reinstall }}" != "true" ]; then
+            echo "When `nix-installer-revision` or `nix-installer-branch` are set the detection of existing installs (and versions) may be unreliable, `reinstall: true` should also be set"
+          fi
+
+          if [ -n "${{ inputs.reinstall }}" ] && [ "${{ inputs.reinstall }}" == "true" ]; then
             /nix/nix-installer uninstall --no-confirm
           else
+            EXISTING_VERSION=$(/nix/nix-installer --version | awk '{ print $2 }')
+            if [ -n "${{ inputs.nix-installer-tag }}" ] && [ "${{ inputs.nix-installer-tag }}" != "$EXISTING_VERSION" ]; then
+              echo "`nix-installer` version mismatch, if attempting to upgrade to a new tag, use `reinstall: true`, you may want to back up your `/nix/store` first"
+              exit 1
+            fi
             echo "Nix was already installed, using existing install"
+            echo "/nix/var/nix/profiles/default/bin" >> $GITHUB_PATH
             exit 0
           fi
-          
         fi
 
         if [ -n "${{ inputs.nix-installer-tag }}" ]; then
-          export NIX_INSTALLER_TAG=${{ inputs.tag }}
+          export NIX_INSTALLER_TAG=${{ inputs.nix-installer-tag }}
           echo "Set NIX_INSTALLER_TAG=$NIX_INSTALLER_TAG"
         fi
         

From 78b28a0bb705e7c84d5925e5b0713f6e857d08d3 Mon Sep 17 00:00:00 2001
From: Ana Hobden <operator@hoverbear.org>
Date: Mon, 16 Jan 2023 09:35:30 -0800
Subject: [PATCH 2/2] Clean up wording

---
 action.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/action.yml b/action.yml
index 074cee5..59d260e 100644
--- a/action.yml
+++ b/action.yml
@@ -76,7 +76,7 @@ inputs:
     description: The branch of `nix-installer` to use
     required: false
   reinstall:
-    description: Force a reinstall if an existing installation is detected
+    description: Force a reinstall if an existing installation is detected  (consider backing up `/nix/store`)
     required: false
 
 runs:
@@ -87,7 +87,7 @@ runs:
       run: |
         if [ -f "/nix/receipt.json" ] && [ -f "/nix/nix-installer" ]; then
           if ([ -n "${{ inputs.nix-installer-revision }}" ] || [ -n "${{ inputs.nix-installer-branch }}" ]) && [ "${{ inputs.reinstall }}" != "true" ]; then
-            echo "When `nix-installer-revision` or `nix-installer-branch` are set the detection of existing installs (and versions) may be unreliable, `reinstall: true` should also be set"
+            echo "Detection of existing installation versions isn't supported when `nix-installer-revision` or `nix-installer-branch` are set, `reinstall: true` should also be set"
           fi
 
           if [ -n "${{ inputs.reinstall }}" ] && [ "${{ inputs.reinstall }}" == "true" ]; then
@@ -95,7 +95,7 @@ runs:
           else
             EXISTING_VERSION=$(/nix/nix-installer --version | awk '{ print $2 }')
             if [ -n "${{ inputs.nix-installer-tag }}" ] && [ "${{ inputs.nix-installer-tag }}" != "$EXISTING_VERSION" ]; then
-              echo "`nix-installer` version mismatch, if attempting to upgrade to a new tag, use `reinstall: true`, you may want to back up your `/nix/store` first"
+              echo "`nix-installer` version mismatch, use `reinstall: true` to reinstall Nix using the new `nix-installer` version (consider backing up `/nix/store`)"
               exit 1
             fi
             echo "Nix was already installed, using existing install"