termux-download silent fail when set a bad destination path

Problem description
When I try to save a downloaded file, using termux-download with -p to a Termux internal path, nothing happens. No error are throw to the console and no notification on the android interface.

It works to /storage/emulated/0/Download/ however it wont work to $HOME/storage/downloads, even with it pointing to the first path.

Steps to reproduce
Step 1 - Run:
termux-download -d 'some picture' -t 'hyperbola' -p $HOME/gnu.jpg http://www.gnu.org/distros/screenshots/hyperbola-i3-thumb.jpg
Step 2 - no step two... that fails without log

Expected behavior
It must show the download on the Android notification and save the file on the destination set with -p parameter.

If it really can't download to $HOME, it must throw an error. It must write to STDERR and exit with a non zero status.

Paths like $HOME/storage/downloads must be translated with realpath by termux-download itself.

Additional information
All tests were made in a emulated device.

Post output of command termux-info.

Packages CPU architecture:
i686
Subscribed repositories:
# sources.list
deb https://grimler.se/termux-packages-24/ stable main
# game-repo (sources.list.d/game.list)
deb https://dl.bintray.com/grimler/game-packages-24 games stable
# science-repo (sources.list.d/science.list)
deb https://dl.bintray.com/grimler/science-packages-24 science stable
# x11-repo (sources.list.d/x11.list)
deb https://dl.bintray.com/xeffyr/x11-packages x11 main
Updatable packages:
apt/stable 2.1.15 i686 [upgradable from: 2.1.11-2]
bash/stable 5.1.4 i686 [upgradable from: 5.0.18-4]
ca-certificates/stable 20201208 all [upgradable from: 20201027]
command-not-found/stable 1.60 i686 [upgradable from: 1.59]
coreutils/stable 8.32-7 i686 [upgradable from: 8.32-6]
curl/stable 7.74.0 i686 [upgradable from: 7.73.0]
dash/stable 0.5.11.3 i686 [upgradable from: 0.5.11.2-4]
dpkg/stable 1.20.5-5 i686 [upgradable from: 1.20.5-4]
gpgv/stable 2.2.26 i686 [upgradable from: 2.2.23]
libcurl/stable 7.74.0 i686 [upgradable from: 7.73.0]
libgmp/stable 6.2.1 i686 [upgradable from: 6.2.0-1]
libgpg-error/stable 1.41 i686 [upgradable from: 1.39]
liblz4/stable 1.9.3 i686 [upgradable from: 1.9.2]
libnettle/stable 3.7 i686 [upgradable from: 3.6]
libnghttp2/stable 1.42.0 i686 [upgradable from: 1.41.0-1]
libtirpc/stable 1.3.1 i686 [upgradable from: 1.2.6-1]
lsof/stable 4.94.0 i686 [upgradable from: 4.93.2]
nano/stable 5.4 i686 [upgradable from: 5.3]
net-tools/stable 2.10.0 i686 [upgradable from: 1.60.2017.02.21-3]
openssl/stable 1.1.1i i686 [upgradable from: 1.1.1h]
readline/stable 8.1.0 i686 [upgradable from: 8.0.4-1]
termux-am/stable 0.4 all [upgradable from: 0.3]
termux-tools/stable 0.104 all [upgradable from: 0.97]
tsu/stable 8.5.1-3 all [upgradable from: 8.5.1-2]
util-linux/stable 2.36.1 i686 [upgradable from: 2.36]
Android version:
8.0.0
Kernel build information:
Linux localhost 4.4.34-genymotion #1 SMP PREEMPT Fri Jan 31 08:31:47 UTC 2020 i686 Android
Device manufacturer:

Device model:
Google Pixel 2 API 8

If you are rooted or have access to adb then capture a logcat with logcat -d "*:W", from a adb or root shell.

01-14 00:20:24.387  3763 16209 E memtrack: Couldn't load memtrack module
01-14 00:20:24.387  3763 16209 W android.os.Debug: failed to get memory consumption info: -1
01-14 00:20:40.927  6605  6605 E DecorView[]: Destroying unexpected ActionMode instance of TYPE_FLOATING; com.android.internal.view.FloatingActionMode@202ff60 was not the current floating action mode! Expected null
01-14 00:20:41.154 16213 16213 W /system/bin/app_process: Unexpected CPU variant for X86 using defaults: x86
01-14 00:20:41.156 16213 16213 W /system/bin/app_process: Could not create mount namespace.
01-14 00:20:41.156 16213 16213 W nativebridge: Failed to bind-mount /system/lib/x86/cpuinfo as /proc/cpuinfo: Operation not permitted
01-14 00:20:41.185 13608 13626 W DownloadManager: Path appears to be invalid: /data/data/com.termux/files/home/storage/downloads/gnu.jpg
01-14 00:20:41.185 13608 13626 W DownloadManager: Path appears to be invalid: /data/data/com.termux/files/home/storage/downloads/gnu.jpg
01-14 00:20:41.185 13608 13626 E DatabaseUtils: Writing exception to parcel
01-14 00:20:41.185 13608 13626 E DatabaseUtils: java.lang.SecurityException: Unsupported path /data/data/com.termux/files/home/storage/downloads/gnu.jpg
01-14 00:20:41.185 13608 13626 E DatabaseUtils: 	at com.android.providers.downloads.DownloadProvider.checkFileUriDestination(DownloadProvider.java:808)
01-14 00:20:41.185 13608 13626 E DatabaseUtils: 	at com.android.providers.downloads.DownloadProvider.insert(DownloadProvider.java:599)
01-14 00:20:41.185 13608 13626 E DatabaseUtils: 	at android.content.ContentProvider$Transport.insert(ContentProvider.java:267)
01-14 00:20:41.185 13608 13626 E DatabaseUtils: 	at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:152)
01-14 00:20:41.185 13608 13626 E DatabaseUtils: 	at android.os.Binder.execTransact(Binder.java:674)
01-14 00:20:41.186 12485 16222 E termux-api: Error in ResultReturner
01-14 00:20:41.186 12485 16222 E termux-api: java.lang.SecurityException: Unsupported path /data/data/com.termux/files/home/storage/downloads/gnu.jpg
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.os.Parcel.readException(Parcel.java:1942)
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:183)
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:135)
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.content.ContentProviderProxy.insert(ContentProviderNative.java:476)
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.content.ContentResolver.insert(ContentResolver.java:1539)
01-14 00:20:41.186 12485 16222 E termux-api: 	at android.app.DownloadManager.enqueue(DownloadManager.java:1041)
01-14 00:20:41.186 12485 16222 E termux-api: 	at com.termux.api.DownloadAPI.lambda$onReceive$0(DownloadAPI.java:41)
01-14 00:20:41.186 12485 16222 E termux-api: 	at com.termux.api.-$$Lambda$DownloadAPI$4YhREMVDJjtX4lY26y4bbDIrLiw.writeResult(Unknown Source:4)
01-14 00:20:41.186 12485 16222 E termux-api: 	at com.termux.api.util.ResultReturner.lambda$returnData$0(ResultReturner.java:133)
01-14 00:20:41.186 12485 16222 E termux-api: 	at com.termux.api.util.-$$Lambda$ResultReturner$oCU8JqHW5HLMrNZa40ThjAWcwzo.run(Unknown Source:8)
01-14 00:20:41.186 12485 16222 E termux-api: 	at java.lang.Thread.run(Thread.java:764)
01-14 00:20:45.441   656  6451 W MessageQueue: Handler (android.media.MediaPlayer$EventHandler) {24659ce} sending message to a Handler on a dead thread
01-14 00:20:45.441   656  6451 W MessageQueue: java.lang.IllegalStateException: Handler (android.media.MediaPlayer$EventHandler) {24659ce} sending message to a Handler on a dead thread
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.os.MessageQueue.enqueueMessage(MessageQueue.java:545)
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.os.Handler.enqueueMessage(Handler.java:661)
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.os.Handler.sendMessageAtTime(Handler.java:630)
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.os.Handler.sendMessageDelayed(Handler.java:600)
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.os.Handler.sendMessage(Handler.java:537)
01-14 00:20:45.441   656  6451 W MessageQueue: 	at android.media.MediaPlayer.postEventFromNative(MediaPlayer.java:3436)

Start with the termux-download entry point and the DownloadAPI.java stack-trace location, then reproduce the -p failure using a Termux-internal path. Check how the failed enqueue result is handled; done means the command reports the failure on STDERR with a non-zero status, while valid destinations still download and notify.