hq/01-RESEARCH/026-the-graphical-session-as-modules/03-what-the-predecessor-taught.md

03 — What the predecessor taught

A study on 2026-10-04 of the retired predecessor:

• its 128 module manifests, their hooks, its installer and its sync engine;
• 3,395 commits of history;
• what it left on four machines.

This document holds what bears on the graphical session and on the system layer (research 027). The evidence is in the predecessor's history. A commit is cited here by what it fixed, not by its hash, because the repository is private.

Keep: what worked

pattern	where it shows	in the mesh
ownership marked inside the file: inside the markers is reconciled, outside is kept verbatim	a block marker in a shared file, after an engine that rewrote whole files	kept regions (ADR 0174, ADR 0204)
two writers get two files and an include, the include first	the ssh client's configuration, after two writers fought over one file	ADR 0203's two files; research 026 C1
one writer per file, one authority per action	only the reload watcher restarts the window manager, after three mechanisms each did	ADR 0182
refuse to write when the source of truth is unreadable; never empty a block because a query found nothing	a block of names was emptied by a failed query	— keep
an unresolved template variable fails the install	a literal unfilled path was installed green	issue 231: the mesh still has this gap
prune only what you can prove you placed	stale files from earlier deliveries	ADR 0189
ensuring never rotates a credential	a silent rotation caused a retry storm, a ban of the shared address and a lost registry	ADR 0114
vendor only the files you use; never clone and link	three files instead of 77 MB	ADR 0205
copy, never symlink	a recursive delete followed a link, and every reinstall failed	ADR 0012
verification says what it did not check	a verifier said clean while the secret was still on disk	— keep
alert once per condition	411 alerts hid a 28-hour outage	ADR 0090

Do not repeat

failure	what it did	the mesh instead	where the mesh is still exposed
Flavors	variant files and packages per machine type: a gate dropped, the first-seen variant won, packages never installed, the verifier ignored the gate. On the day of the study a desktop carried a laptop model's fragments	one module per piece, assignment per machine (ADR 0174, research 026 §1)	a setting that switches which whole file is rendered is a flavor under another name
The freeze	existing values outranked new defaults; templated files were rendered once (copy if absent)	files are generated (ADR 0011)	a created-once file (ADR 0087) is a deliberate freeze, and a push must say kept
Adopting drift	a merge strategy made a local edit the record forever; switching strategies clobbered a person's model choice	nothing is read back (ADR 0174)	an edit outside a kept region is overwritten silently. The predecessor's why is this back loop: the push should name what it overwrote
Environment templating	${VAR} matched any name; unresolved names stayed literal; comments and destination paths were interpolated	namespaced placeholders; $ forbidden in contributed values (ADR 0203)	issue 231
Hooks with privilege	install hooks ran sudo, chsh, systemctl, git clone and curl, and swallowed failures into a warning	the user shape, the service shape, archives (ADR 0176, 0177, 0205)	the agent module writes under /etc from its own tool through sudo (no keep-original, no give-back); the prompt's helper downloads itself unpinned; that the operator escalates without a prompt is assumed by three modules and declared by none (research 027)
Secrets in environment files	.env files left world-readable; the decryption key beside what it decrypts; a deleted secret stayed in the file, so rotation was a no-op	the vault (ADR 0113, 0114)	a predecessor file of secrets is still sourced into the graphical session on two machines (research 027 Q2)
Symlinks into a home	a system file linked into a person's home	ADR 0012	on the control machine, a fail2ban action file is still a predecessor link into its home tree. Deleting that tree would silently break the repeat-offender jail. The mesh's fail2ban module must own it as a file first
Green while broken	a recorded version frozen for four months; a verifier passing what it skipped	ADR 0134, 0145, 0184	issue 230: a plan waiting for ever reads as healthy

What it means here

• Research 026: the desktop's 88 flavor-gated files and 92 theme variables are the flavor and templating failures in one module. Question 1 (one module per piece) and question 6 (hardware modules, settings later) are the answer, and nothing in the new modules may switch whole files on a setting.
• Research 027: the hooks that installed the AUR helper, enabled the login manager and changed shells are what the package, service and user shapes replace. Every remaining sudo in a module's own code is a debt to be named, starting with the agent module.