From 16b72ed6e02f6b8bae4ec84f23d45f877f9d7f0e Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Fri, 6 Feb 2026 14:15:19 +0100
Subject: [PATCH 01/27] feat: Test Action

---
 .github/workflows/test.yml | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 .github/workflows/test.yml

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..eb99b2a
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,16 @@
+name: "Test"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    container:
+      image: catthehacker/ubuntu:act-latest
+    steps:
+    - uses: actions/checkout@v5
+    - uses: https://github.com/cachix/install-nix-action@v31
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
+    - name: "My custom step"
+      run: nix run nixpkgs#hello

From bc8118b48a9dbfc3192f82daa2a979882f15fc64 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 11:57:18 +0100
Subject: [PATCH 02/27] chore: Disable test workflow

---
 .github/workflows/test.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index eb99b2a..8cb0f4b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -4,6 +4,7 @@ on:
   push:
 jobs:
   tests:
+    if: false
     runs-on: ubuntu-latest
     container:
       image: catthehacker/ubuntu:act-latest

From 90bd5ed66bf670329327c824efd3e5d2a57689cf Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 11:57:38 +0100
Subject: [PATCH 03/27] Determine hosts

---
 .github/workflows/build.yml | 34 ++++++++++++++++++++++++++++++++++
 .gitignore                  |  1 +
 2 files changed, 35 insertions(+)
 create mode 100644 .github/workflows/build.yml

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..2a1fb35
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,34 @@
+name: "Build"
+on:
+  pull_request:
+
+jobs:
+  determine_hosts:
+    name: "Determining hosts to build"
+    runs-on: ubuntu-latest
+    container:
+      image: catthehacker/ubuntu:act-latest
+
+    steps:
+      - uses: actions/checkout@v5
+      - uses: https://github.com/cachix/install-nix-action@v31
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+      - name: "List hosts"
+        id: hosts
+        run: nix eval .#nixosConfigurations --apply builtins.attrNames --json
+    outputs:
+      hosts: ${{ steps.hosts.outputs }}
+
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: catthehacker/ubuntu:act-latest
+    needs: determine_hosts
+    strategy:
+      matrix:
+        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
+
+    steps:
+      - run: echo "${{ matrix.hostname }}"
+
diff --git a/.gitignore b/.gitignore
index 485dee6..8daf605 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .idea
+result

From 4103c488b3958413b5c135fd751b9421ab01c62c Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 11:58:43 +0100
Subject: [PATCH 04/27] Build each host

---
 .github/workflows/build.yml | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2a1fb35..482df03 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -16,7 +16,8 @@ jobs:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: "List hosts"
         id: hosts
-        run: nix eval .#nixosConfigurations --apply builtins.attrNames --json
+        run: |
+          nix eval .#nixosConfigurations --apply builtins.attrNames --json
     outputs:
       hosts: ${{ steps.hosts.outputs }}
 
@@ -30,5 +31,11 @@ jobs:
         hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
 
     steps:
-      - run: echo "${{ matrix.hostname }}"
+      - name: "Define host"
+        env:
+          hostname: ${{ matrix.hostname }}
+        run: |
+          echo "${hostname}"
+      - run: |
+          nixos-rebuild build --flake ".#${hostname}"
 

From 60fe8110b1249ca3751419c21be2fc05be25dfd7 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:00:31 +0100
Subject: [PATCH 05/27] Add NixOS to build step as well

---
 .github/workflows/build.yml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 482df03..44248aa 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -31,6 +31,10 @@ jobs:
         hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
 
     steps:
+      - uses: actions/checkout@v5
+      - uses: https://github.com/cachix/install-nix-action@v31
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: "Define host"
         env:
           hostname: ${{ matrix.hostname }}

From bfbe4204e75de965f8cbcdf3bb2cb72c83b96615 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:04:02 +0100
Subject: [PATCH 06/27] More specific hostnames

---
 .github/workflows/build.yml | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 44248aa..baafa8e 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,7 +17,8 @@ jobs:
       - name: "List hosts"
         id: hosts
         run: |
-          nix eval .#nixosConfigurations --apply builtins.attrNames --json
+          hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
+          echo "hostnames=${hosts}" >> "$GITHUB_OUTPUT"
     outputs:
       hosts: ${{ steps.hosts.outputs }}
 
@@ -28,7 +29,7 @@ jobs:
     needs: determine_hosts
     strategy:
       matrix:
-        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
+        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts.hostnames) }}
 
     steps:
       - uses: actions/checkout@v5
@@ -39,7 +40,7 @@ jobs:
         env:
           hostname: ${{ matrix.hostname }}
         run: |
-          echo "${hostname}"
+          echo "Hostname: ${hostname}"
       - run: |
           nixos-rebuild build --flake ".#${hostname}"
 

From cef1259f8d76e8f699a87736a8c56cafd042ad10 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:06:26 +0100
Subject: [PATCH 07/27] fix json elements

---
 .github/workflows/build.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index baafa8e..de0b62b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,7 +20,7 @@ jobs:
           hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
           echo "hostnames=${hosts}" >> "$GITHUB_OUTPUT"
     outputs:
-      hosts: ${{ steps.hosts.outputs }}
+      hosts: ${{ steps.hosts.outputs.hostnames }}
 
   build:
     runs-on: ubuntu-latest
@@ -29,7 +29,7 @@ jobs:
     needs: determine_hosts
     strategy:
       matrix:
-        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts.hostnames) }}
+        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
 
     steps:
       - uses: actions/checkout@v5

From 7d8a6693c1ff9bd2f32bb6dde6f1be5145b79caf Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:14:07 +0100
Subject: [PATCH 08/27] try different way

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index de0b62b..13865b6 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -40,7 +40,7 @@ jobs:
         env:
           hostname: ${{ matrix.hostname }}
         run: |
-          echo "Hostname: ${hostname}"
+          echo "Hostname: ${{ matrix.hostname }}"
       - run: |
           nixos-rebuild build --flake ".#${hostname}"
 

From 2996df479f1f898e433052f6ce672145eda7082f Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:17:33 +0100
Subject: [PATCH 09/27] Debug matrix

---
 .github/workflows/build.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 13865b6..766266c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -36,6 +36,8 @@ jobs:
       - uses: https://github.com/cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
+      - name: Debug Matrix
+        run: echo "The matrix value is: [${{ matrix.hostname }}]"
       - name: "Define host"
         env:
           hostname: ${{ matrix.hostname }}

From b5af201e86aa8f59a45334c22f4db23669d5bedf Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:18:59 +0100
Subject: [PATCH 10/27] run on push

---
 .github/workflows/build.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 766266c..9e11680 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,6 +1,7 @@
 name: "Build"
 on:
   pull_request:
+  push:
 
 jobs:
   determine_hosts:

From fce4a03fa5878aaa2946b336ca166a789c630a85 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:25:00 +0100
Subject: [PATCH 11/27] use var directly

---
 .github/workflows/build.yml | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9e11680..d59217a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -40,10 +40,8 @@ jobs:
       - name: Debug Matrix
         run: echo "The matrix value is: [${{ matrix.hostname }}]"
       - name: "Define host"
-        env:
-          hostname: ${{ matrix.hostname }}
         run: |
-          echo "Hostname: ${{ matrix.hostname }}"
+          echo "Building for: ${{ matrix.hostname }}"
       - run: |
-          nixos-rebuild build --flake ".#${hostname}"
+          nixos-rebuild build --flake ".#${{ matrix.hostname }}"
 

From 675204152d62b97a871bddd3364cf73b4dbf15e8 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:25:52 +0100
Subject: [PATCH 12/27] fix mappings

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d59217a..7738210 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -38,7 +38,7 @@ jobs:
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: Debug Matrix
-        run: echo "The matrix value is: [${{ matrix.hostname }}]"
+        run: echo "The matrix value is: [ ${{ matrix.hostname }} ]"
       - name: "Define host"
         run: |
           echo "Building for: ${{ matrix.hostname }}"

From 99141d2c7a37bcf47741b639e131f92dece82d24 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:26:31 +0100
Subject: [PATCH 13/27] fix mappings

---
 .github/workflows/build.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7738210..f095725 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -38,7 +38,8 @@ jobs:
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: Debug Matrix
-        run: echo "The matrix value is: [ ${{ matrix.hostname }} ]"
+        run: |
+          echo "The matrix value is: ${{ matrix.hostname }}"
       - name: "Define host"
         run: |
           echo "Building for: ${{ matrix.hostname }}"

From 3e78d7e0f77e9767fc3a06796a5ed78856e638f0 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:29:05 +0100
Subject: [PATCH 14/27] add toolcache

---
 .github/workflows/build.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f095725..3295110 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -3,6 +3,9 @@ on:
   pull_request:
   push:
 
+env:
+  RUNNER_TOOL_CACHE: /toolcache
+
 jobs:
   determine_hosts:
     name: "Determining hosts to build"

From de54d86be1c78f1b04441a9a414420f85511b818 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 12:33:23 +0100
Subject: [PATCH 15/27] Change names and ordere

---
 .github/workflows/build.yml | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3295110..ca38b1a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,12 +7,13 @@ env:
   RUNNER_TOOL_CACHE: /toolcache
 
 jobs:
-  determine_hosts:
+  determine-hosts:
     name: "Determining hosts to build"
     runs-on: ubuntu-latest
     container:
       image: catthehacker/ubuntu:act-latest
-
+    outputs:
+      hosts: ${{ steps.hosts.outputs.hostnames }}
     steps:
       - uses: actions/checkout@v5
       - uses: https://github.com/cachix/install-nix-action@v31
@@ -22,18 +23,16 @@ jobs:
         id: hosts
         run: |
           hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
-          echo "hostnames=${hosts}" >> "$GITHUB_OUTPUT"
-    outputs:
-      hosts: ${{ steps.hosts.outputs.hostnames }}
+          echo "hostnames=${hosts}" >> $GITHUB_OUTPUT
 
   build:
     runs-on: ubuntu-latest
     container:
       image: catthehacker/ubuntu:act-latest
-    needs: determine_hosts
+    needs: determine-hosts
     strategy:
       matrix:
-        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}
+        hostname: ${{ fromJSON(needs.determine-hosts.outputs.hosts) }}
 
     steps:
       - uses: actions/checkout@v5

From 4eff2772d12a9b61091d261bc285fb02ae5b7a03 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 14:50:41 +0100
Subject: [PATCH 16/27] Debugging

---
 .github/workflows/build.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ca38b1a..9950555 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,6 +23,7 @@ jobs:
         id: hosts
         run: |
           hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
+          echo "${hosts}"
           echo "hostnames=${hosts}" >> $GITHUB_OUTPUT
 
   build:

From 478ace7bb43babf31e979ec338e0bc79ec01feb3 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 14:54:31 +0100
Subject: [PATCH 17/27] Debugging extra step

---
 .github/workflows/build.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9950555..e950a7b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -19,12 +19,15 @@ jobs:
       - uses: https://github.com/cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
-      - name: "List hosts"
+      - name: "Determine hosts"
         id: hosts
         run: |
           hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
           echo "${hosts}"
           echo "hostnames=${hosts}" >> $GITHUB_OUTPUT
+      - name: "List hosts"
+        run: |
+          echo "${{ steps.hosts.outputs.hostnames }}"
 
   build:
     runs-on: ubuntu-latest

From 4245b09a71a7b98385893b86a3b4a886e166c1bb Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 14:58:21 +0100
Subject: [PATCH 18/27] Debugging needs outputs

---
 .github/workflows/build.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e950a7b..1b14f27 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -25,7 +25,7 @@ jobs:
           hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
           echo "${hosts}"
           echo "hostnames=${hosts}" >> $GITHUB_OUTPUT
-      - name: "List hosts"
+      - name: "List hosts of step"
         run: |
           echo "${{ steps.hosts.outputs.hostnames }}"
 
@@ -43,6 +43,9 @@ jobs:
       - uses: https://github.com/cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
+      - name: "Debug needs outputs"
+        run: |
+          echo "${{ needs.determine-hosts.outputs }}"
       - name: Debug Matrix
         run: |
           echo "The matrix value is: ${{ matrix.hostname }}"

From bc42639059125dfa42f216acb86b9cf220448dc0 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 14:59:10 +0100
Subject: [PATCH 19/27] Debugging needs outputs hosts

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1b14f27..9455028 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -45,7 +45,7 @@ jobs:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: "Debug needs outputs"
         run: |
-          echo "${{ needs.determine-hosts.outputs }}"
+          echo "${{ needs.determine-hosts.outputs.hosts }}"
       - name: Debug Matrix
         run: |
           echo "The matrix value is: ${{ matrix.hostname }}"

From 8824ee080ccd8c75b6cc7338ca865dde769f224f Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:08:55 +0100
Subject: [PATCH 20/27] Preserve quotes

---
 .github/workflows/build.yml | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9455028..d4b53ca 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,12 +22,8 @@ jobs:
       - name: "Determine hosts"
         id: hosts
         run: |
-          hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
-          echo "${hosts}"
-          echo "hostnames=${hosts}" >> $GITHUB_OUTPUT
-      - name: "List hosts of step"
-        run: |
-          echo "${{ steps.hosts.outputs.hostnames }}"
+          hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
+          printf "hostnames=%s\n" "${hostnames}" >> "${GITHUB_OUTPUT}" # Preserve quotes
 
   build:
     runs-on: ubuntu-latest

From 9008b6ab3d9c2e80152720f105cd3a0d6c3176d1 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:09:38 +0100
Subject: [PATCH 21/27] printf escaped

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d4b53ca..26bd67d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,7 +23,7 @@ jobs:
         id: hosts
         run: |
           hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
-          printf "hostnames=%s\n" "${hostnames}" >> "${GITHUB_OUTPUT}" # Preserve quotes
+          printf "hostnames=%q \n" "${hostnames}" >> "${GITHUB_OUTPUT}" # Preserve quotes
 
   build:
     runs-on: ubuntu-latest

From 02f2ade703f802237cbb24d4dc7342fc45c01172 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:16:02 +0100
Subject: [PATCH 22/27] Using EOF

---
 .github/workflows/build.yml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 26bd67d..7a98325 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,7 +23,11 @@ jobs:
         id: hosts
         run: |
           hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
-          printf "hostnames=%q \n" "${hostnames}" >> "${GITHUB_OUTPUT}" # Preserve quotes
+          {
+            echo "hostnames<<EOF"
+            echo "${hostnames}"
+            echo EOF
+          } >> "${GITHUB_OUTPUT}" # Preserve quotes
 
   build:
     runs-on: ubuntu-latest

From 44131ad8e77d8c530f5933c010e5d27942b8c90b Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:17:34 +0100
Subject: [PATCH 23/27] test

---
 .github/workflows/build.yml | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7a98325..e24ffc9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,11 +23,7 @@ jobs:
         id: hosts
         run: |
           hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
-          {
-            echo "hostnames<<EOF"
-            echo "${hostnames}"
-            echo EOF
-          } >> "${GITHUB_OUTPUT}" # Preserve quotes
+          printf "hostnames=%s\n" "${hostnames}" >> "${GITHUB_OUTPUT}"
 
   build:
     runs-on: ubuntu-latest
@@ -45,7 +41,7 @@ jobs:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: "Debug needs outputs"
         run: |
-          echo "${{ needs.determine-hosts.outputs.hosts }}"
+          printf "%s\n" "${{ needs.determine-hosts.outputs.hosts }}"
       - name: Debug Matrix
         run: |
           echo "The matrix value is: ${{ matrix.hostname }}"

From ea3492ee27ec0e2ea7aaed945b412e0deda61025 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:26:27 +0100
Subject: [PATCH 24/27] escape?

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e24ffc9..a2dd14e 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,7 +22,7 @@ jobs:
       - name: "Determine hosts"
         id: hosts
         run: |
-          hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
+          hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json | tr '\n' ', ' | sed 's/,$//')"
           printf "hostnames=%s\n" "${hostnames}" >> "${GITHUB_OUTPUT}"
 
   build:

From a5ed47a4783b6be2233d71bde6fc69aa7fe78537 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:30:52 +0100
Subject: [PATCH 25/27] without json parse

---
 .github/workflows/build.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a2dd14e..7926715 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,7 +22,7 @@ jobs:
       - name: "Determine hosts"
         id: hosts
         run: |
-          hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json | tr '\n' ', ' | sed 's/,$//')"
+          hostnames="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
           printf "hostnames=%s\n" "${hostnames}" >> "${GITHUB_OUTPUT}"
 
   build:
@@ -32,7 +32,7 @@ jobs:
     needs: determine-hosts
     strategy:
       matrix:
-        hostname: ${{ fromJSON(needs.determine-hosts.outputs.hosts) }}
+        hostname: ${{ needs.determine-hosts.outputs.hosts }}
 
     steps:
       - uses: actions/checkout@v5

From 3d4082c25c06741297ee5cb53e921e8e54731d3f Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:35:02 +0100
Subject: [PATCH 26/27] hardcoding

---
 .github/workflows/build.yml | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7926715..ca96545 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -32,22 +32,17 @@ jobs:
     needs: determine-hosts
     strategy:
       matrix:
-        hostname: ${{ needs.determine-hosts.outputs.hosts }}
+        hostname: [
+          Development
+          Testing
+        ]
 
     steps:
       - uses: actions/checkout@v5
       - uses: https://github.com/cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
-      - name: "Debug needs outputs"
+      - name: "Build host"
         run: |
-          printf "%s\n" "${{ needs.determine-hosts.outputs.hosts }}"
-      - name: Debug Matrix
-        run: |
-          echo "The matrix value is: ${{ matrix.hostname }}"
-      - name: "Define host"
-        run: |
-          echo "Building for: ${{ matrix.hostname }}"
-      - run: |
           nixos-rebuild build --flake ".#${{ matrix.hostname }}"
 

From b9bd093ba878bffdfddf9f35e4735191c84fd654 Mon Sep 17 00:00:00 2001
From: Tibo De Peuter <tibo@depeuter.dev>
Date: Sun, 8 Feb 2026 15:38:18 +0100
Subject: [PATCH 27/27] change build command

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ca96545..cce5071 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -44,5 +44,5 @@ jobs:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: "Build host"
         run: |
-          nixos-rebuild build --flake ".#${{ matrix.hostname }}"
+          nix build ".#nixosConfigurations.${{ matrix.hostname }}.config.system.build.toplevel"