notes on how-to migrate old machines

1 files changed, 79 insertions, 2 deletions

diff --git a/README.md b/README.md
index a3cb8df..9fa73c5 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ deploy:
     - tags
   tags: [source]
 ```
-      
+
 **Note**: If you're using Git submodules, please follow [Using Git submodules with GitLab CI](https://docs.gitlab.com/ee/ci/git_submodules.html) to prepare your repository and modify the `upload` stage in the `.gitlab-ci.yml` according to your requirements.
 
 #### Trigger a build
@@ -118,4 +118,81 @@ For the time being, all patches must remain in `./` to be found by guix, due to:
               (string-append directory "/gnu/packages/patches")
               directory))
         %load-path)))
-```
\ No newline at end of file
+```
+
+## Troubleshooting
+
+When you are upgrading from a old installation, you might face issues where `%default-channels` points to previous guix and nongnu (nonguix) channels.
+
+Here's what your channels file probably looked like:
+
+```scheme
+(list (channel
+        (name 'guix)
+        (url "https://channels.pantherx.org/git/pantherx.git")
+        (branch "rolling-nonlibre"))
+      (channel
+        (name 'nongnu)
+        (url "https://channels.pantherx.org/git/nongnu.git")
+        (branch "rolling"))
+      (channel
+        (name 'pantherx)
+        (url "https://channels.pantherx.org/git/pantherx-extra.git")
+        (branch "master")))
+```
+
+This is what you tried:
+
+```scheme
+(cons* (channel
+        (name 'pantherx)
+        (branch "master")
+        (url "https://channels.pantherx.org/git/panther.git")
+         (introduction
+          (make-channel-introduction
+           "54b4056ac571611892c743b65f4c47dc298c49da"
+           (openpgp-fingerprint
+            "A36A D41E ECC7 A871 1003  5D24 524F EB1A 9D33 C9CB"))))
+       %default-channels)
+```
+
+This is a potential issue:
+
+```bash
+zcat /var/log/guix/drvs/k7/dgx55ivy7bfgm2z2qvk0njnjs2x5dh-nongnu.drv.gz
+(repl-version 0 1 1)
+(exception unbound-variable (value #f) (value "Unbound variable: ~S") (value (linux-libre-6.3)) (value #f))
+```
+
+This is how you can temporarily overwrite all channels:
+
+```scheme
+(list (channel
+       (name 'guix)
+       (branch "master")
+       (url "https://git.savannah.gnu.org/git/guix.git")
+        (introduction
+         (make-channel-introduction
+          "9edb3f66fd807b096b48283debdcddccfea34bad"
+          (openpgp-fingerprint
+           "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"))))
+       (channel
+        (name 'nonguix)
+        (url "https://channels.pantherx.org/git/nonguix.git")
+        (introduction
+         (make-channel-introduction
+          "897c1a470da759236cc11798f4e0a5f7d4d59fbc"
+          (openpgp-fingerprint
+           "2A39 3FFF 68F4 EF7A 3D29  12AF 6F51 20A0 22FB B2D5"))))
+       (channel
+        (name 'pantherx)
+        (branch "master")
+        (url "https://channels.pantherx.org/git/panther.git")
+         (introduction
+          (make-channel-introduction
+           "54b4056ac571611892c743b65f4c47dc298c49da"
+           (openpgp-fingerprint
+            "A36A D41E ECC7 A871 1003  5D24 524F EB1A 9D33 C9CB")))))
+```
+
+After pull and reconfigure succeeds, you may restore the default.