Fail more gracefully if the tzdb failed to initialize

Now, not everything will break, but only the calls to timezone
facilities.

Author: dkhalanskyjb

core/darwin/src/internal/TimeZoneNative.kt

@@ -10,7 +10,9 @@ import kotlinx.cinterop.*
 import kotlinx.datetime.internal.*
 import platform.Foundation.*
 
-internal actual val systemTzdb: TimeZoneDatabase = TzdbOnFilesystem(Path.fromString(defaultTzdbPath()))
+internal actual val systemTzdb: TimeZoneDatabase get() = tzdb.getOrThrow()
+
+private val tzdb = runCatching { TzdbOnFilesystem(Path.fromString(defaultTzdbPath())) }
 
 internal expect fun defaultTzdbPath(): String
 

core/linux/src/internal/TimeZoneNative.kt

@@ -5,7 +5,9 @@
 
 package kotlinx.datetime.internal
 
-internal actual val systemTzdb: TimeZoneDatabase = TzdbOnFilesystem()
+internal actual val systemTzdb: TimeZoneDatabase get() = tzdb.getOrThrow()
+
+private val tzdb = runCatching { TzdbOnFilesystem() }
 
 internal actual fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?> {
     val zoneId = pathToSystemDefault()?.second?.toString()

core/windows/src/internal/TimeZoneNative.kt

@@ -5,8 +5,9 @@
 
 package kotlinx.datetime.internal
 
-internal actual val systemTzdb: TimeZoneDatabase get() = tzdbInRegistry
+internal actual val systemTzdb: TimeZoneDatabase get() = tzdbInRegistry.getOrThrow()
 
-internal actual fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?> = tzdbInRegistry.currentSystemDefault()
+internal actual fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?> =
+    tzdbInRegistry.getOrThrow().currentSystemDefault()
 
-private val tzdbInRegistry = TzdbInRegistry()
+private val tzdbInRegistry = runCatching { TzdbInRegistry() }