ghc/ghc-triggered builds fail to start properly

Here is an excerpt from the most recent attempt:

Skipping Git submodules setup
Checking cache for build-HEAD...
No URL provided, cache will not be downloaded from shared cache server. Instead a local version of cache will be extracted. 
Successfully extracted cache

$ if [ -n "$GHC_PIPELINE_ID" ]; then # collapsed multi-line command
error: getting status of '/builds/ghc/head.hackage/scripts/build-all.nix': No such file or directory
Running after script...
$ ls -lh
total 40K    
-rw-rw-rw-    1 root     root        7.1K Nov 20 10:19 README.md
drwxrwxrwx    2 root     root        4.0K Nov 20 10:19 ci
-rw-rw-rw-    1 root     root        3.9K Nov 20 10:19 default.nix
-rw-rw-rw-    1 root     root         648 Nov 20 10:19 ghc-from-source.nix
-rw-rw-rw-    1 root     root         510 Nov 20 10:19 ghc-prerelease.nix
-rw-rw-rw-    1 root     root        1.1K Nov 20 10:19 http-api-data.nix
drwxrwxrwx    2 root     root        4.0K Nov 20 10:19 patches
-rwxrwxrwx    1 root     root        1.4K Nov 20 10:19 run-ci
drwxrwxrwx    2 root     root        4.0K Nov 20 10:19 scripts
$ nix run -f ./ci -c \ # collapsed multi-line command
tar: can't change directory to 'ci/run': No such file or directory
Uploading artifacts...
results.tar.xz: found 1 matching files             
Uploading artifacts to coordinator... ok            id=206485 responseStatus=201 Created token=xqowfzPG
ERROR: Job failed: exit code 1