Possible bug: Weird crash, not sure the cause

[AndroidDeveloperLB]

implementation("com.github.topjohnwu.libsu:core:6.0.0")

Got recently this crash from Crashlytics:

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.OutputStream java.lang.Process.getOutputStream()' on a null object reference
       at com.topjohnwu.superuser.internal.ShellImpl$NoCloseOutputStream.<init>(ShellImpl.java:102)
       at com.topjohnwu.superuser.internal.ShellImpl.<init>(ShellImpl.java:123)
       at com.topjohnwu.superuser.internal.BuilderImpl.build(BuilderImpl.java:136)
       at com.topjohnwu.superuser.internal.BuilderImpl.exec(BuilderImpl.java:119)
       at com.topjohnwu.superuser.internal.Utils.setConfirmedRootState(Utils.java:78)
       at com.topjohnwu.superuser.internal.BuilderImpl.start(BuilderImpl.java:107)
       at com.topjohnwu.superuser.internal.BuilderImpl.build(BuilderImpl.java:158)
       at com.topjohnwu.superuser.NoShellException.<init>(NoShellException.java:27)
       at com.topjohnwu.superuser.internal.MainShell.get(MainShell.java:48)
       at com.topjohnwu.superuser.internal.MainShell.returnShell(MainShell.java:60)
       at com.topjohnwu.superuser.internal.MainShell.lambda$get$1(MainShell.java:74)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
       at java.lang.Thread.run(Thread.java:923)

It doesn't show on the stacktrace anything about my app.
However, I have some logs I've reported before, which might help.

if (savedInstanceState == null) {
    val cachedShell = Shell.getCachedShell()
    if (cachedShell?.isRoot == false)
        cachedShell.close()
    viewModel.getRoot()
}

The getRoot is as such:

@UiThread
fun getRoot() {
    Shell.getShell {
        val hasRoot = it.isRoot
        liveData.value = StatefulData.Success(hasRoot)
    }
}

Sadly I don't know what was truly called here, but pretty sure it entered this block of code because that's the only place that uses the library at this point.