fix(library-select): honor Arduino library spec for 1.0 flat layout; release v2.2.6

[zackees]

Closes #267 (Fix 2 — scanner correctness). Cuts release v2.2.6.

The bug

fbuild 2.2.5 fails to build any sketch for teensy41:

fatal error: ft2build.h: No such file or directory
   23 | #include <ft2build.h>
compilation terminated.

The offending file is framework-arduinoteensy/libraries/ssd1351/fontconvert/fontconvert.c — a host-only desktop tool that links -lfreetype. ssd1351 ships it as a font preprocessor; it was never meant to be ARM-cross-compiled.

Root cause

collect_library_sources in framework_library.rs walked the entire library directory recursively for 1.0 flat-layout libraries (no src/), violating the Arduino library spec:

• 1.5 recursive layout (has src/): scan src/** only.
• 1.0 flat layout (no src/): scan root non-recursively plus literal utility/.

Subdirectories like fontconvert/, util/, Fonts/, examples/, extras/ must be ignored. The ssd1351 author parked fontconvert.c in fontconvert/ (not utility/) precisely so Arduino IDE and PlatformIO would skip it. fbuild's recursive walk swept it in.

Fix

Rewrite collect_library_sources to dispatch on layout — 1.5 stays recursive into src/; 1.0 is non-recursive at root plus a single recurse into utility/. Matches arduino-cli exactly.

Regression tests

• collect_library_sources_flat_layout_arduino_spec — ssd1351 fixture. Asserts root + utility/ only; fontconvert/ + util/ + Fonts/ + examples/ are all dropped.
• collect_library_sources_recursive_layout_arduino_spec — src/ fixture. Asserts only src/**; root-level baz.cpp dropped.

Release v2.2.6

Cargo + pyproject bumped to 2.2.6. On merge, release-auto.yml triggers (path filter matches Cargo.toml + pyproject.toml).

Deferred (separate work)

Fix 1 from #267 — investigate why ssd1351 is reaching the compile set at all when Blink doesn't #include <ssd1351.h>. With Fix 2 in place, even if ssd1351 IS selected, only ssd1351.cpp at the root would be compiled (which cross-compiles fine for ARM). The user-reported build failure is resolved by Fix 2 alone.

Test plan

• soldr cargo check --workspace --all-targets — clean
• soldr cargo clippy --workspace --all-targets -- -D warnings — clean
• soldr cargo fmt --all -- --check — clean
• soldr cargo test --workspace — all green; new framework_library tests pass
• CI passes
• release-auto.yml ships v2.2.6 to PyPI + GitHub
• FastLED's bash compile teensy41 succeeds on v2.2.6

🤖 Generated with Claude Code

Summary by CodeRabbit

• Chores

  • Version updated to 2.2.6

• Bug Fixes

  • Improved library source collection handling. Libraries with src/ directories now recursively scan only that directory, while libraries without src/ scan the root non-recursively plus the utility/ subdirectory. Other subdirectories are now properly excluded.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 46c0d0c9-ad44-40c7-89d2-ef7360ff10a7

📥 Commits

Reviewing files that changed from the base of the PR and between 48bf377 and fc2d61c.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (3)

• Cargo.toml
• crates/fbuild-packages/src/library/framework_library.rs
• pyproject.toml

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📝 Walkthrough

Walkthrough

This PR fixes Arduino library specification compliance in source discovery. The library scanner now correctly dispatches on layout type: 1.5 layouts with src/ directories scan only src/** recursively, while 1.0 flat layouts scan the root non-recursively and utility/ recursively, ignoring other subdirectories. Workspace and project versions are bumped to 2.2.6.

Changes

Arduino Library Specification Compliance

Layer / File(s)	Summary
Arduino spec-compliant library source collection crates/fbuild-packages/src/library/framework_library.rs	Entry point collect_library_sources dispatches on layout type: recursive src/** scan for 1.5 layouts (when src/ exists), or non-recursive root scan plus recursive utility/-only scan for 1.0 flat layouts. Refactored with collect_root_level_sources helper and is_buildable_source filter (c/cpp/cc/cxx/s extensions). Recursive walker defensively skips examples/, tests/, extras/. Prior test replaced with new regression tests for both layouts.
Workspace and project version synchronization Cargo.toml, pyproject.toml	Version bumped from 2.2.5 to 2.2.6 in both Rust workspace and Python project configuration.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• FastLED/fbuild#203: Modifies Arduino framework library source discovery in the same crates/fbuild-packages/src/library/framework_library.rs file, with this PR refining scan rules for src/ vs flat layouts that directly affect the resolver introduced in #203.

Poem

🐰 Hop along, dear builders true,
Now our specs are tried and true!
Flat or nested, src or root,
Arduino knows the scanner's route.
No fontconvert in the compile set—
fbuild 2.2.6 won't forget! 🎉

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main changes: fixing Arduino library spec compliance for flat-layout libraries and releasing v2.2.6.
Linked Issues check	✅ Passed	The PR successfully implements Fix 2 from issue #267 with comprehensive changes to honor Arduino library spec, including flat-layout and recursive-layout source collection and regression tests.
Out of Scope Changes check	✅ Passed	All changes are in scope: version bumps in Cargo.toml and pyproject.toml align with the v2.2.6 release, and the library scanner refactoring directly addresses the Arduino spec violation.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/267-arduino-lib-spec

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