[Google Pixel 2 XL Questions & Answers] raynan:
I've been researching this for the past few days and haven't found anything particularly helpful and I'm just curious to see if anyone else has tried this or has a solution. Running the "screencap" command as root on my 2 XL running 8.1 no longer works, regardless of any options; if I did my research correctly, it's complaining about the gralloc HAL not running in passthrough mode, but I don't know what to do with this information. If anyone is familiar with gralloc, here's the logcat:

12-17 21:17:18.070 6854 6854 F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
12-17 21:17:18.070 6854 6854 F DEBUG : Build fingerprint: 'google/taimen/taimen:8.1.0/OPM1.171019.011/4448085:user/release-keys'
12-17 21:17:18.070 6854 6854 F DEBUG : Revision: 'rev_10'
12-17 21:17:18.070 6854 6854 F DEBUG : ABI: 'arm64'
12-17 21:17:18.070 6854 6854 F DEBUG : pid: 6850, tid: 6850, name: screencap >>> screencap <<<
12-17 21:17:18.070 6854 6854 F DEBUG : signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
12-17 21:17:18.071 6854 6854 F DEBUG : Abort message: 'gralloc-mapper must be in passthrough mode'
12-17 21:17:18.071 6854 6854 F DEBUG : x0 0000000000000000 x1 0000000000001ac2 x2 0000000000000006 x3 0000000000000008
12-17 21:17:18.071 6854 6854 F DEBUG : x4 0000000000000000 x5 0000000000000000 x6 0000000000000000 x7 7f7f7f7f7f7f7f7f
12-17 21:17:18.071 6854 6854 F DEBUG : x8 0000000000000083 x9 0000000010000000 x10 0000007fc90b9860 x11 0000000000000001
12-17 21:17:18.071 6854 6854 F DEBUG : x12 0000007fc90b9980 x13 ffffffffffffffff x14 ff00000000000000 x15 ffffffffffffffff
12-17 21:17:18.071 6854 6854 F DEBUG : x16 0000007811ed62e8 x17 0000007811e33178 x18 0000000000000001 x19 0000000000001ac2
12-17 21:17:18.071 6854 6854 F DEBUG : x20 0000000000001ac2 x21 0000000000000083 x22 0000000000000001 x23 0000000000000b40
12-17 21:17:18.071 6854 6854 F DEBUG : x24 00000000000005a0 x25 000000778f66f1c0 x26 0000007812849a40 x27 0000000000000010
12-17 21:17:18.071 6854 6854 F DEBUG : x28 0000007fc90b9f39 x29 0000007fc90b98a0 x30 0000007811e28760
12-17 21:17:18.071 6854 6854 F DEBUG : sp 0000007fc90b9860 pc 0000007811e28788 pstate 0000000060000000
12-17 21:17:18.079 6854 6854 F DEBUG :
12-17 21:17:18.079 6854 6854 F DEBUG : backtrace:
12-17 21:17:18.079 6854 6854 F DEBUG : #00 pc 000000000001d788 /system/lib64/libc.so (abort+120)
12-17 21:17:18.079 6854 6854 F DEBUG : #01 pc 0000000000007f08 /system/lib64/liblog.so (__android_log_assert+296)
12-17 21:17:18.079 6854 6854 F DEBUG : #02 pc 0000000000014290 /system/lib64/libui.so (android::Gralloc2::Mapper::Mapper()+256)
12-17 21:17:18.079 6854 6854 F DEBUG : #03 pc 0000000000017ab0 /system/lib64/libui.so (android::GraphicBufferMapper::GraphicBufferMapper()+28)
12-17 21:17:18.079 6854 6854 F DEBUG : #04 pc 00000000000154c0 /system/lib64/libui.so (android::GraphicBuffer::GraphicBuffer()+140)
12-17 21:17:18.079 6854 6854 F DEBUG : #05 pc 00000000000156d8 /system/lib64/libui.so (android::GraphicBuffer::GraphicBuffer(unsigned int, unsigned int, int, unsigned int, unsigned long, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>)+68)
12-17 21:17:18.079 6854 6854 F DEBUG : #06 pc 0000000000057c60 /system/lib64/libgui.so (android::BufferQueueProducer::dequeueBuffer(int*, android::sp<android::Fence>*, unsigned int, unsigned int, int, unsigned long, unsigned long*, android::FrameEventHistoryDelta*)+2264)
12-17 21:17:18.079 6854 6854 F DEBUG : #07 pc 000000000006ba50 /system/lib64/libgui.so (android::BnGraphicBufferProducer::onTransact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+448)
12-17 21:17:18.079 6854 6854 F DEBUG : #08 pc 000000000004ae38 /system/lib64/libbinder.so (android::BBinder::transact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+136)
12-17 21:17:18.079 6854 6854 F DEBUG : #09 pc 0000000000054dec /system/lib64/libbinder.so (android::IPCThreadState::executeCommand(int)+528)
12-17 21:17:18.079 6854 6854 F DEBUG : #10 pc 00000000000556a0 /system/lib64/libbinder.so (android::IPCThreadState::waitForResponse(android::Parcel*, int*)+340)
12-17 21:17:18.079 6854 6854 F DEBUG : #11 pc 00000000000553ec /system/lib64/libbinder.so (android::IPCThreadState::transact(int, unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+224)
12-17 21:17:18.079 6854 6854 F DEBUG : #12 pc 000000000004c230 /system/lib64/libbinder.so (android::BpBinder::transact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+72)
12-17 21:17:18.079 6854 6854 F DEBUG : #13 pc 0000000000072ab4 /system/lib64/libgui.so (android::BpSurfaceComposer::captureScreen(android::sp<android::IBinder> const&, android::sp<android::IGraphicBufferProducer> const&, android::Rect, unsigned int, unsigned int, int, int, bool, android::ISurfaceComposer::Rotation)+364)
12-17 21:17:18.079 6854 6854 F DEBUG : #14 pc 00000000000865ac /system/lib64/libgui.so (android::ScreenshotClient::update(android::sp<android::IBinder> const&, android::Rect, unsigned int, unsigned int, int, int, bool, unsigned int)+284)
12-17 21:17:18.079 6854 6854 F DEBUG : #15 pc 0000000000001dc4 /system/bin/screencap (main+572)
12-17 21:17:18.079 6854 6854 F DEBUG : #16 pc 00000000000a1cec /system/lib64/libc.so (__libc_init+88)
12-17 21:17:18.079 6854 6854 F DEBUG : #17 pc 0000000000001ae8 /system/bin/screencap (_start_main+80)