[MarcZX10]

What

Carries the chflags implementation from issue #3632. It validates the guest path, reports missing and unsupported flag errors, rejects SF_SNAPSHOT, and throws an explicit unsupported-host error when asked to set recognized BSD file flags that the host does not store.

PPSA99420 reaches the chflags import on current main now that its earlier stops have merged (issue #1578). This PR carries only chflags; the other calls from #3632 are separate changes.

Tested

• Before this current-main rebase, Linux Release GCC 12.2 built guest_filesystem_tests; CTest guest_filesystem passed 1/1.
• Conventions and git diff --check passed on that earlier head.
• The current-main rebase has not been built or tested locally. CI/reviewer validation should rerun on this head.

Checklist

• Based on current main; no open PR implements the same function
• One topic: chflags
• No comments in code except technical debt
• No notes or investigation files added
• Generic behavior, not title-specific
• Depends on: none (the earlier prerequisite PRs have merged)
• Unblocks: PPSA99420 Four open-source homebrew titles stop at start-up on unresolved imports (sysctl, pthread_set_name_np, isatty, mkstemp, signal sets, Opus decoders) #1578
• AI-assisted: yes

[github-actions]

Progress report (0aa4cb1 → b6a10e9)

📈 System libraries: 88.16% (+0.01%, +1 implemented functions)

✅ 1 implemented

Library	Name
libkernel	chflags_nid_postfix

[MarcZX10]

The PR description was corrected to use the template section headings (### What, ### Tested, ### Checklist) and now passes the local conventions checker. The current hosted conventions result reflects the earlier body. Posting this update to trigger a fresh PR check against the corrected description.

[reyani-dev]

Title path for this one, from a Windows run (catalog build, main e013f8c + #3980 + #3893 + #3781):

• PS5MC (PPSA99420) stops at FAIL: unresolved ELF import ixrw0h2tWuI from libkernel.prx (chflags). With a chflags export added, its next stop is miQ1wVwSexE (getpriority, feat(libkernel): implement getpriority for the guest process #4374).
• The only call site (guest 0x3C9100A) is the bundled CPython's os.chflags (chflags($module, /, path, flags, follow_symlinks=True); the lchflags branch sits next to it). CPython's shutil.copystat calls os.chflags(dst, st.st_flags) when both exist, so any shutil.copy2/copytree in a Kodi add-on reaches it.
• NativeStat zero-initialises FileStat (*sb = FileStat{};) and nothing sets st_flags, so that call is always chflags(path, 0). That's the path this PR answers with 0 after the lookup.

[blawesom]

Rebase handoff — rebased onto current main, authorship unchanged.

One conflict in Stdio.cpp, resolved by keeping both sides: main's newer File::DuplicateFrom (the guest-socket descriptor duplication) and this PR's LookupError + chflags tables are independent additions at the same spot. TechnicalDebt.md unioned.

Verified on Linux (CachyOS, kernel 7.2.9, GCC 16.2.1, Ninja, Release, BUILD_TESTING=ON, AMD RX 9070 XT / RADV):

• builds; tools/check_conventions.py --base origin/main passes
• full suite: 955/955 passed

To pick it up:

git fetch https://github.com/blawesom/AnyPS5 rebase/4379
git checkout <your branch>
git merge --ff-only FETCH_HEAD

Head is fdfdc9435.

[screamm]

Windows validation with title evidence (Windows 11 Pro 26220, WinLibs MinGW-w64 GCC 15.2.0 r7, Ninja, Release, BUILD_TESTING=ON, full build including libs; base main 2a2a3dc6): 71fbc3ce merges cleanly but does not compile on current main: Stdio.cpp:308:22: error: redefinition of 'constexpr const int GUEST_EOPNOTSUPP', because main already has static constexpr int GUEST_EOPNOTSUPP = 45; since e99816e8 (#4391); the rebase only needs to drop the PR's copy (same value). With that one line removed: guest_filesystem 3/3; suite 688/689, the only failure being patched_libraries, which fails on main itself until #5025; conventions and git diff --check pass.

PS5MC (PPSA99420) relinked against that build: before, FAIL: unresolved ELF import ixrw0h2tWuI from libkernel.prx (chflags); after, FAIL: unresolved ELF import miQ1wVwSexE from libkernel.prx (getpriority, #4374). Stacked with #4374 and #4383 (plus a one-line test fix on #4383, see there) the title goes on to FAIL: unresolved ELF import d7nUj1LOdDU from libkernel.prx (clock_settime, the last commit of my #3632 branch).

[p3n1cillin]

Title run with this PR: Windows 11, MinGW GCC 15.2.0 (WinLibs), Release. Built on main 3faa9cb40 merged with this PR and the other open PRs that the catalog titles below need (#4377, #4379, #4374, #4383, #3798, #4863, #4105, my #5013/#5061/#5078/#5098/#5009 and the carries #5183/#5186, plus screamm's chroot branch from #3632); every title converted from its catalog release, eboot.bin kept in app0, 60 s runs.

• PS5MC (PPSA99420): with this PR, feat(libkernel): implement getpriority for the guest process #4374, feat(libkernel): implement sigpending #4383 and feat(libkernel): add clock_settime with FreeBSD argument checks #5183 (clock_settime) it loads; tools/import_audit.py lists no absent import. It then needs feat(libkernel): report vm.overcommit through sysctlbyname #5184, feat(libkernel): report _SC_CLK_TCK through sysconf #5185 and fix(libkernel): handle FIOCLEX and FIONCLEX in ioctl #5186 to get through Kodi's start-up, after which Kodi creates its GUI and runs 90 s.

Build problem at this head (71fbc3ce6): core/libs/prx/libkernel/File/src/Stdio.cpp defines static constexpr int GUEST_EOPNOTSUPP = 45; twice (lines 302 and 308), so GCC 15 stops with redefinition of 'constexpr const int GUEST_EOPNOTSUPP'. One of the two lines needs to go; I dropped line 308 locally for the run above.

AI-assisted (Claude Code).

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
#4973	core/libs/prx/libkernel/File/src/Stdio.cpp L31

[MarcZX10]

The title-run report identified a duplicate GUEST_EOPNOTSUPP definition in Stdio.cpp; I removed the redundant definition in commit b6a10e91a. tools/check_conventions.py --base upstream/main and git diff --check pass. I attempted a fresh Linux Release configure, but it stopped before compilation because this worktree's SDL2 submodule is uninitialized and the environment lacks XRandR development support. The hosted PR checks are running against this head.

[MarcZX10]

Follow-up verification on the pushed head b6a10e91a: Linux x86-64, GCC 12.2, Ninja Release, fresh CMake configure with pinned submodules initialized. The guest_filesystem_tests target built successfully (including Stdio.cpp), and ctest -R '^guest_filesystem$' passed (1/1). This closes the local compile/test gap noted in my earlier update.