iOS: file-only :inet_db lookup by default in Mob.App.start/0 - #14
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C-Sinclair wants to merge 1 commit into
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iOS: file-only :inet_db lookup by default in Mob.App.start/0#14C-Sinclair wants to merge 1 commit into
C-Sinclair wants to merge 1 commit into
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iOS sandboxes execve of any binary the app didn't get a special pass for, and BEAM's default :native hostname resolver spawns the inet_gethost port program — so the first Node.connect / :erpc.call / gen_tcp.connect/3 with a binary host crashed with :badarg before this. The sim hits the same failure for a related-but-distinct reason (inet_gethost isn't where BEAM expects in the mob iOS-sim OTP layout). Mob.App.configure_ios_inet_db/0 sets the lookup chain to [:file] and seeds localhost. Called as the first line of the macro-generated start/0 so app on_start/0 never has to think about it. Gated on :mob_nif.platform() == :ios (host BEAM and Android untouched); guarded with try/rescue so the NIF-not-loaded case (host test BEAM) doesn't crash. Composes cleanly with Mob.DNS.configure_pure_beam/1 — apps that need outbound DNS layer it on top to upgrade [:file] → [:file, :dns]; the file-table entries seeded here stay ahead and keep winning.
GenericJam
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May 20, 2026
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Thanks @C-Sinclair — landed as 11752a4 in mob 0.6.15 with your authorship preserved. CHANGELOG resolution merged both your The framework now owns the |
pshoukry pushed a commit
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Sep 9, 2026
…ixed (mob_new + mob_dev companion commits) Four small lost-in-the-shuffle items closed in this batch. All four were held up by Phase 2 work touching the same files (GenericJam#1/GenericJam#2/GenericJam#4 in live_view_patcher.ex; GenericJam#5 in native_build.ex). GenericJam#1 — Phoenix LiveReload mac_listener warnings: code_reloader/watchers/ live_reload disabled in on-device endpoint config. GenericJam#2 — esbuild/tailwind version-not-configured warnings: versions set via Application.put_env in mob_app.ex before ensure_all_started. GenericJam#4 — port 4200 collisions across multiple Mob LV apps: per-app hash into 4200..4999 via :erlang.phash2(:<app>, 800). GenericJam#5 — deploy auto-pick of iPhone over sim was silent: prints the --device <short-id> alternative when both are connected. GenericJam#3 (WS→longpoll fallback in WKWebView) is investigation, not a fix — deferred. GenericJam#6-GenericJam#11 are larger work (OTP rebuild, AX modifiers, Compose semantics walker, Android 17 SELinux patch). GenericJam#12, GenericJam#13 already fixed earlier. GenericJam#14 is moderate — sim node naming reconciliation between mob_dev's connect.ex and mob_beam.m, deferred.
pshoukry pushed a commit
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Sep 9, 2026
…d-around GenericJam#7 + GenericJam#8 — `MobSlider` and `MobToggle` in MobRootView.swift gained the SwiftUI AX modifiers SwiftUI doesn't apply by default (.accessibilityAdjustableAction with default step (max-min)/10 for the slider; .accessibilityLabel(label) for the toggle). Mob.Test end-to-end driving works after these. GenericJam#14 — defensive fallback in MobDev.Connector. When the primary node name times out the connector now also tries the alternate `<app>_ios@127.0.0.1` form (without the udid suffix). The connected Device.node is updated to whichever responded so downstream RPC calls use the correct address. The root cause (mob_beam.m sometimes not seeing SIMULATOR_UDID) is captured in the resolution note for a future investigation. Remaining: GenericJam#3 (WebSocket→longpoll, investigation), GenericJam#6 (16 KB page alignment, OTP rebuild), GenericJam#9 (Alert OK button, UIKit deep dive), GenericJam#10 (Android 17 SELinux, OTP source patch), GenericJam#11 (Android Compose semantics walker, ~200 lines Kotlin).
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Summary
Mob.App.start/0now switches:inet_db's lookup chain to[:file]and seedslocalhoston iOS, before any user code runs. The firstNode.connect/:erpc.call/gen_tcp.connect/3with a binary host no longer crashes the calling process with:badarg.Why
BEAM's default
:nativehostname resolution spawns theinet_gethostport program. iOS's app sandbox forbidsexecveof any binary the app didn't get a special pass for, so the spawn fails categorically on device. The simulator hits the same failure for a related-but-distinct reason —inet_gethostdoesn't live at the path BEAM expects under the mob iOS-sim OTP layout. Either way, the lookup dies and any caller through:inet.getaddr/2(distribution, RPC, TCP-by-name) gets:badargand exits.Every iOS mob app today has to do this dance manually in
on_start/0before anything touches a hostname:Easy to forget, impossible to test for, and bites every new consumer the first time they call
:erpc.call. The framework should own this.Composability with
Mob.DNSPure addition.
Mob.DNS.configure_pure_beam/1keeps working — it upgrades[:file]→[:file, :dns]and seeds fallback nameservers. The file-table entries this PR adds stay first in the chain and keep winning, so the two layers compose:[:file], distribution + local-loopback TCP work. No DNS.Mob.DNS.configure_pure_beam/1for outbound HTTP — chain becomes[:file, :dns], fallback nameservers (Google + Cloudflare by default) handle public hosts.Mob.DNS.resolve/1for VPN / mDNS / search-domain semantics — Apple resolver via NIF, result seeded in the file table, always wins because:fileis first.Apps that want the default OS resolver back (and were somehow getting away with it on iOS) can call
:inet_db.set_lookup([:native])in their ownon_start/0, which runs afterstart/0.Why
[:file]not[:file, :dns]by defaultConservative — the irreducible fix is preventing the
inet_gethostspawn. Adding:dnsto the framework default would mean every iOS app pays for fallback-nameserver state it may not use, and apps that talk to an internal-only backend on a fixed IP get a slightly-noisierinet_db.Mob.DNS.configure_pure_beam/1is the right opt-in for apps that need DNS; the framework just guarantees the crash doesn't happen.Test plan
mix test— 798 passed (27 doctests, 771 tests), 43 excluded. Newtest/mob/app_test.exsverifies the host-BEAM (NIF-unloaded) path is a no-op and that the function is idempotent.mix format --check-formatted— cleanmix credo --strict— clean (952 mods/funs, 0 issues)mix compile --warnings-as-errors— cleanmix erlfmt --check src/— clean:erpc.callfrom a sim app crashes withinet_gethostopen_port:badarg, and with the fix the same call succeeds.Related
Companion to the other small contributions in this series —
text-field-secure(#12),fix/ios-column-fill-height,scroll-on-refresh,nav-transition-override. Each stands alone; land in any order.