Tor doesn't start with targetSdkVersion set to 29
As expected, Android's restrictions on launching processes are getting tighter. Setting the targetSdkVersion to 29 prevents Tor from starting on the API 29 emulator:
2020-03-30 17:46:55.672 7943-8057/org.briarproject.briar.android.debug I/TorPlugin: Starting Tor
2020-03-30 17:46:55.680 7943-8057/org.briarproject.briar.android.debug W/PluginManagerImpl: org.briarproject.bramble.api.plugin.PluginException: java.io.IOException: Cannot run program "/data/user/0/org.briarproject.briar.android.debug/app_tor/tor" (in directory "/data/user/0/org.briarproject.briar.android.debug/app_tor"): error=13, Permission denied
org.briarproject.bramble.api.plugin.PluginException: java.io.IOException: Cannot run program "/data/user/0/org.briarproject.briar.android.debug/app_tor/tor" (in directory "/data/user/0/org.briarproject.briar.android.debug/app_tor"): error=13, Permission denied
at org.briarproject.bramble.plugin.tor.TorPlugin.start(TorPlugin.java:221)
at org.briarproject.bramble.plugin.PluginManagerImpl$PluginStarter.run(PluginManagerImpl.java:220)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:923)
Caused by: java.io.IOException: Cannot run program "/data/user/0/org.briarproject.briar.android.debug/app_tor/tor" (in directory "/data/user/0/org.briarproject.briar.android.debug/app_tor"): error=13, Permission denied
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1050)
at org.briarproject.bramble.plugin.tor.TorPlugin.start(TorPlugin.java:219)
at org.briarproject.bramble.plugin.PluginManagerImpl$PluginStarter.run(PluginManagerImpl.java:220)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:923)
Caused by: java.io.IOException: error=13, Permission denied
at java.lang.UNIXProcess.forkAndExec(Native Method)
at java.lang.UNIXProcess.<init>(UNIXProcess.java:133)
at java.lang.ProcessImpl.start(ProcessImpl.java:141)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
at org.briarproject.bramble.plugin.tor.TorPlugin.start(TorPlugin.java:219)
at org.briarproject.bramble.plugin.PluginManagerImpl$PluginStarter.run(PluginManagerImpl.java:220)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:923)
Tor starts OK with the current targetSdkVersion of 28. Same results on the API 30 emulator.