Support iOS-only development on a Mac (don't crash when adb is absent)#29
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`mix mob.connect` (and any tunnel path) crashed with `:enoent` for a
Mac set up only for iOS: the dist-port collision check shelled out to
`adb forward --list`, and `System.cmd("adb", ...)` *raises* for a missing
binary rather than returning a non-zero exit. The raise happened inside a
linked `Task.async`, so the exit propagated and killed the whole connect.
Two parts:
1. Bug fix — `MobDev.Tunnel.run_adb/1` resolves `adb` via
`System.find_executable/1` first (mirroring `Discovery.Android.list_devices/0`)
and returns `{:error, "adb not found on PATH"}` when absent. Every caller
already handles `{:error, _}`, so the port scan / cleanup degrade to "no
adb forwards" instead of crashing. iOS-only Macs now work with no adb at all.
2. Explicit iOS-only mode — `mix mob.connect --ios-only` / `--android-only`
restrict discovery to one platform, and a `mob.exs` default
(`config :mob_dev, platforms: [:ios]`) makes it project-wide so a Mac-only
iOS dev sets it once. Skipping the Android scan also avoids sweeping in a
phone plugged in for some other project.
New pure kernels with tests: `MobDev.Config.parse_platforms/1`,
`Mix.Tasks.Mob.Connect.resolve_platforms/2`, plus a regression test that
`Tunnel.ports_in_use/1` degrades to a MapSet when adb is off PATH.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Jun 29, 2026
…s absent) mix mob.connect no longer crashes with :enoent when adb isn't installed (Tunnel.run_adb guards on System.find_executable). Adds --ios-only / --android-only and a `config :mob_dev, platforms: [:ios]` default. (#29) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Problem
On a Mac set up only for iOS (no Android platform-tools),
mix mob.connectcrashes:The dist-port collision check (
Tunnel.ports_in_use/1→forward_host_ports/0) shells out toadb forward --list.System.cmd("adb", ...)raises:enoentfor a missing binary rather than returning a non-zero exit, and because it runs inside a linkedTask.async, the crash propagates an exit that kills the whole connect. The existing{:error, _} -> MapSet.new()fallback never gets a chance to run.iOS-only on a Mac is fully supported (the simulator shares the Mac's network stack — no tunnels needed); adb should simply never be required.
Fix
1. Robustness (the actual bug).
Tunnel.run_adb/1now resolvesadbviaSystem.find_executable/1first — the same guardDiscovery.Android.list_devices/0already uses — and returns{:error, "adb not found on PATH"}when it's absent. Every caller already handles{:error, _}, so the port scan and forward cleanup degrade to "no adb forwards" instead of crashing. iOS-only Macs now work with no adb installed at all.2. Explicit iOS-only mode (requested ergonomic). Even when adb is present, you can scope a session:
mix mob.connect --ios-only/--android-onlymob.exsso a Mac-only iOS dev sets it once:Tests (pure kernels + regression)
MobDev.Config.parse_platforms/1— nil/valid/filtered/invalid/non-list matrixMix.Tasks.Mob.Connect.resolve_platforms/2— flag precedence + both-flags errorMobDev.TunnelAdbMissingTest— withadboff PATH,ports_in_use/1returns aMapSetinstead of crashing (locks the regression)31 targeted tests pass. Pre-existing unrelated failures (HotPush/enable/adopt/tflite/ndk — environmental) were confirmed failing on the base before this change too.
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