Unable to detect the scanner

[andrewshvv]

Hey!

I am using mac os + virtual box + docker with ubuntu 20.04.

I have successfully installed all the packages and was able to start the example script. I have forwarded USB port and able to see the content when using "cat /dev/ttyUSB0" and scanning the QR code. The command lsusb also shows that the scanner has been identified.

But script is not seeing the scanner, is there any way to debug the issue?

root@9f026fa7afd2:/home/statistics# lsusb
Bus 001 Device 008: ID 05e0:1200 Symbol Technologies, Inc, 2008 Symbol Bar Code Scanner::EA
Bus 001 Device 001: ID 1d6b:0001

Output in docker container when scanning something:

root@9f026fa7afd2:/home/statistics# cat /dev/ttyUSB0
@X�A9���C-p�_C�
             @X�A9���S-<p�_p����@X�A9���C-p�_@X�A9���S-<p�_?R���@X�A9���C-

... more gibberish...

root@9f026fa7afd2:/home/statistics# uname -a
Linux 9f026fa7afd2 4.19.130-boot2docker #1 SMP Mon Jun 29 23:52:55 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

root@9f026fa7afd2:/home/statistics# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.1 LTS
Release:    20.04
Codename:   focal

docker-compose.yaml:

version: "3.8"

services:
  statistics:
    build:
      context: ./src/statistics
    container_name: statistics
    devices:
      - "/dev/usbmon0:/dev/ttyUSB0"

    # Wait for one minute for gracefull shutdown
    stop_grace_period: 1m

    # Restart on exit.
    restart: always

Dockerfile

# set base image (host OS)
FROM fnndsc/ubuntu-python3:latest

RUN apt-get update \
    && apt-get install -y \
        wget \
        unzip \
        git \
        usbutils \
        pkg-config \
        libudev-dev \
        libboost-dev \
        libboost-python-dev \
        libpugixml-dev \
        python-dev

RUN apt-get install -y openjdk-8-jdk
ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk
ENV PATH=$PATH:$JAVA_HOME/bin
RUN java -version

RUN wget "https://www.zebra.com/content/dam/zebra_new_ia/en-us/software/developer-tools/scanner-sdk-for-linux/SDK_for_Linux_v4.4.1-15_Debian_Packages_x86_64bit_C98.zip" \
    && unzip "SDK_for_Linux_v4.4.1-15_Debian_Packages_x86_64bit_C98.zip" \
    && cd SDK_for_Linux_v4.4.1-15_Debian_Packages_x86_64bit_C98 \
    && dpkg -i zebra-scanner-corescanner_4.4.1-15_amd64.deb \
    && dpkg -i zebra-scanner-corescanner-dbg_4.4.1-15_amd64.deb \
    && dpkg -i zebra-scanner-devel_4.4.1-15_amd64.deb \
    && dpkg -i zebra-scanner-javapos_4.4.1-14_amd64.deb

RUN pip3 install pybind11
RUN pip3 install git+https://github.com/dayjaby/zebra-scanner@d497feb7f2ab825131708e68d8e5f828faaa6f70

# set the working directory in the container
WORKDIR /home/statistics

# ensure that Python outputs everything that's printed inside
# the application rather than buffering it.
ENV PYTHONUNBUFFERED 1

# cope source files
COPY . .

# install dependencies
RUN pip3 install -r requirements.txt

# command to run on container start
ENTRYPOINT [ "bash", "entrypoint.sh" ] # I then go to the docker and executre the python script

[andrewshvv]

Using strace I was able to see the write in the zebra-scanner log, the content of the log if:

root@d8cb2364e817:/home/statistics# cat /var/log/zebra-scanner/corescannerd/*
OS name : Ubuntu | OS version : 20.04.1 LTS (Focal Fossa) | kernal version : 4.19.130-boot2docker | system architecture : x86_64 | gcc version : 5.4.0 20160609 | udev version : /lib/x86_64-linux-gnu/libudev.so.1 | java version : openjdk 1.8.0_275 | libusb version : 1.0.9.0 | corescanner version :  4.4.1-15
20201211 | 18:26:52:282 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [571] | INFO | | | Open calling ConnectN
20201211 | 18:26:52:283 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsConnector.cpp [48] | ERROR | | | Can't connect to corescanner. Returned error code : 111
20201211 | 18:26:52:283 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [574] | INFO | | | Open ConnectN return STATUS_ERROR
20201211 | 18:26:52:283 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [563] | INFO | | | Open sAppName: legacyXml, iScannerType: 65535
OS name : Ubuntu | OS version : 20.04.1 LTS (Focal Fossa) | kernal version : 4.19.130-boot2docker | system architecture : x86_64 | gcc version : 5.4.0 20160609 | udev version : /lib/x86_64-linux-gnu/libudev.so.1 | java version : openjdk 1.8.0_275 | libusb version : 1.0.9.0 | corescanner version :  4.4.1-15
20201211 | 18:26:52:377 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [571] | INFO | | | Open calling ConnectN
20201211 | 18:26:52:377 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsConnector.cpp [48] | ERROR | | | Can't connect to corescanner. Returned error code : 111
20201211 | 18:26:52:378 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [574] | INFO | | | Open ConnectN return STATUS_ERROR
20201211 | 18:27:06:148 | CLIENTLIB_COMMON | | | 31 | 139755555563328 | CsClientApiCore.cpp [606] | INFO | | | Close starting

The most useful line for you might be this:

OS name : Ubuntu | OS version : 20.04.1 LTS (Focal Fossa) | kernal version : 4.19.130-boot2docker | system architecture : x86_64 | gcc version : 5.4.0 20160609 | udev version : /lib/x86_64-linux-gnu/libudev.so.1 | java version : openjdk 1.8.0_275 | libusb version : 1.0.9.0 | corescanner version :  4.4.1-15

[andrewshvv]

@Sthing, @dayjaby I would appreciate your feedback. If you think this question is out of your scope of expertise or you just don't have time atm, please notify me. In this case, I will probably move on and would use some other environment setup, cause I run out of problem hypotheses.

[Sthing]

Hi @andrewshvv .

Have you tried the linux sample app (/usr/share/zebra-scanner/samples/gui-app/bin/corescanner-gui-app)? That shoud work after installing the Zebra .deb-files. I guess that unless the sample app works there is no chance to get the python-binding working.

[andrewshvv]

@Sthing Thanks for the response!

No, I haven't tried it, I will, thanks!

[andrewshvv]

Seems as if I still haven't setup scanner properly, ::ExecCommand(CMD_RSM_ATTR_GETALL, inXml, outXml, &sId); returns STATUS_ERROR.

(gdb)  list "Scanner::FetchAttributes()"
204     // in our on_scanner_added callback
205     s.FetchAttributes("0");
206     OnScannerAdded(o);
207 }
208
209 void Scanner::FetchAttributes() {
210     std::string inXml = "<inArgs><scannerID>"+scannerID+"</scannerID></inArgs>";
211     StatusID sId;
212     std::string outXml;
213
(gdb)
214     ::ExecCommand(CMD_RSM_ATTR_GETALL, inXml, outXml, &sId);
215
216     pugi::xml_document outargs;
217     outargs.load_buffer_inplace(&outXml[0], outXml.size());
218     std::string attribute_list;
219     bool first = true;
220     for(pugi::xml_node attr = outargs.child("outArgs").child("arg-xml").child("response").child("attrib_list").child("attribute");
221             attr;
222             attr = attr.next_sibling("attribute")) {
223         if(!first)
(gdb)
224             attribute_list += ',';
225         attribute_list += attr.child_value();
226         first = false;
227     }
228     FetchAttributes(attribute_list);
229 }
230
231 void Scanner::FetchAttributes(std::string attribute_list) {
232     std::string inXml = "<inArgs><scannerID>" + scannerID +
233                         "</scannerID><cmdArgs><arg-xml><attrib_list>" +
(gdb) b "/home/statistics/zebra-scanner/src/BoostPythonCoreScanner.cpp:219"
Breakpoint 12 at 0x7ffff7988cec: file /home/statistics/zebra-scanner/src/BoostPythonCoreScanner.cpp, line 219.
(gdb) continue
Continuing.
[Switching to Thread 0x7ffff691e700 (LWP 171)]

Thread 3 "python3" hit Breakpoint 12, Scanner::FetchAttributes (this=0x7fffe80091a0) at /home/statistics/zebra-scanner/src/BoostPythonCoreScanner.cpp:220
220     for(pugi::xml_node attr = outargs.child("outArgs").child("arg-xml").child("response").child("attrib_list").child("attribute");
(gdb) info locals
attr = {_root = 0x7ffff691ccf0}
inXml = "<inArgs><scannerID>1</scannerID></inArgs>"
sId = STATUS_ERROR
outXml = ""
outargs = {<pugi::xml_node> = {_root = 0x7ffff691cc68}, _buffer = 0x0,
  _memory = "\250\314\221\366\377\177", '\000' <repeats 18 times>, "\330\177", '\000' <repeats 14 times>, "\001(", '\000' <repeats 38 times>, "h\314\221\366\377\177", '\000' <repeats 18 times>, "@\314\221\366\377\177\000\000\330\177\000\000\000\000\000\000\340\313\221\366\377\177\000\000\000\000\000\000\000\000\000\000\374\202\231\367\377\177\000\000\340\314\221\366\377\177\000\000\000\000\000\000\000\000\000\000\060o\376\365\377\177", '\000' <repeats 18 times>, "@o\376\365\377\177\000"}
attribute_list = ""
first = true
(gdb)

CMD_RSM_ATTR_GETALL = 0x1388 (5000)

Log:

20201217 | 14:38:30:993 | CORESCANNER | | | 20 | 139774719411968 | CsClient.cpp [30] | INFO | | | cmd = 5000, cmd_id = 15, data_length = 4
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774719411968 | CsClient.cpp [234] | INFO | | | Routing Cmd to device
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774719411968 | CsClient.cpp [236] | INFO | | | Cmd Data|(4 bytes) = 00 00 00 01
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774719411968 | CsDeviceManager.cpp [1131] | INFO | | | CMD issued to a base device, device index is: 1
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774719411968 | CsDeviceManager.cpp [1135] | INFO | | | Addressed Device found
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774727804672 | CsOneConsumerManyProducersQ.h [80] | INFO | | | OneConsumerManyProducersQ::Consume: time_wait returns true
20201217 | 14:38:30:994 | CORESCANNER | | | 20 | 139774727804672 | CsOneConsumerManyProducersQ.h [105] | INFO | | | OneConsumerManyProducersQ::Consume: m_Queue.size(): 1
20201217 | 14:38:30:995 | CORESCANNER | | | 20 | 139774727804672 | CsDeviceHidkb.cpp [126] | ERROR | | | CommLib don't know how to handle opcode 5000
20201217 | 14:38:30:995 | CORESCANNER | | | 20 | 139774727804672 | CsDevice.cpp [216] | ERROR | | | Command failed

[andrewshvv]

Okay.... completely accidentally I have installed an extension for Virtualbox, and turned on USB 2.0, instead of USB 1.0. Now I receive all information, but I scan the QR code it ends with segmentation fault:

root@86e40ac01a45:/home/statistics# python3 main.py
cat: write error: Broken pipe
New scanner found: <F6041394E2C0499E8DE4625340FC109A>
None
dict_items([(0, <zebra_scanner.Attribute object at 0x7fa053da8e70>)])
{'datatype': 'F', 'id': 0, 'permission': 7, 'value': True}
Registering scanner -F6041394E2C0499E8DE4625340FC109A-
Start
New scanner found: <F6041394E2C0499E8DE4625340FC109A>
None
dict_items([(0, <zebra_scanner.Attribute object at 0x7fa053da8070>)])
{'datatype': 'F', 'id': 0, 'permission': 7, 'value': True}
Registering scanner -F6041394E2C0499E8DE4625340FC109A-
None
Scanned:
pSHPs0924B381501JX 3
Segmentation fault (core dumped)

VirtualBox 6.1.16 Oracle VM VirtualBox Extension Pack

Support for USB 2.0 and USB 3.0 devices, VirtualBox RDP, disk encryption, NVMe and PXE boot for Intel cards. See this chapter from the User Manual for an introduction to this Extension Pack. The Extension Pack binaries are released under the VirtualBox Personal Use and Evaluation License (PUEL). Please install the same version extension pack as your installed version of VirtualBox.

[dayjaby]

Can you share your main.py or run your gdb analysis again?

[andrewshvv]

Currently trying to rebuild zebra-scanner with -O0 flag in order to get a bit more info in gdb

[andrewshvv]

Barcode scanned successfully and triggers the print:

@scanner.on_barcode
        def on_barcode(barcode):
            print("Scanned:")
            print(barcode.code, barcode.type)

Output: 
Scanned:
pSHPs0924B381501JX 3

But at the event of Barcode deallocation segfault happens:

(gdb) list
756 #endif
757
758 /// RAII wrapper that temporarily clears any Python error state
759 struct error_scope {
760     PyObject *type, *value, *trace;
761     error_scope() { PyErr_Fetch(&type, &value, &trace); }
762     ~error_scope() { PyErr_Restore(type, value, trace); }
763 };
764
765 /// Dummy destructor wrapper that can be used to expose classes with a private destructor
(gdb) list pybind11::class_<Barcode>::dealloc
1504            }
1505            init_holder(inst, v_h, (const holder_type *) holder_ptr, v_h.value_ptr<type>());
1506        }
1507
1508        /// Deallocates an instance; via holder, if constructed; otherwise via operator delete.
1509        static void dealloc(detail::value_and_holder &v_h) {
1510            // We could be deallocating because we are cleaning up after a Python exception.
1511            // If so, the Python error indicator will be set. We need to clear that before
1512            // running the destructor, in case the destructor code calls more Python.
1513            // If we don't, the Python API will exit with an exception, and pybind11 will
(gdb)
1514            // throw error_already_set from the C++ destructor which is forbidden and triggers
1515            // std::terminate().
1516            error_scope scope;
1517            if (v_h.holder_constructed()) {
1518                v_h.holder<holder_type>().~holder_type();
1519                v_h.set_holder_constructed(false);
1520            }
1521            else {
1522                detail::call_operator_delete(v_h.value_ptr<type>(),
1523                    v_h.type->type_size,
(gdb)
1524                    v_h.type->type_align
1525                );
1526            }
1527            v_h.value_ptr() = nullptr;
1528        }
1529
1530        static detail::function_record *get_function_record(handle h) {
1531            h = detail::get_function(h);
1532            return h ? (detail::function_record *) reinterpret_borrow<capsule>(PyCFunction_GET_SELF(h.ptr()))
1533                     : nullptr;
(gdb) s

Thread 3 "python3" received signal SIGSEGV, Segmentation fault.
0x0000000000558f6f in PyErr_Fetch ()
(gdb) info frames
Undefined info command: "frames".  Try "help info".
(gdb) backtrace
#0  0x0000000000558f6f in PyErr_Fetch ()
#1  0x00007ffff794a583 in pybind11::error_scope::error_scope (this=0x7ffff68ce3c0) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/detail/common.h:761
#2  0x00007ffff79676fd in pybind11::class_<Barcode>::dealloc (v_h=...) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/pybind11.h:1516
#3  0x00007ffff7952761 in pybind11::detail::clear_instance (self=0x7ffff79e8fb0) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/detail/class.h:402
#4  0x00007ffff7952863 in pybind11::detail::pybind11_object_dealloc (self=0x7ffff79e8fb0) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/detail/class.h:422
#5  0x00007ffff7944ac9 in _Py_DECREF (filename=0x7ffff7988028 "/usr/include/python3.8/object.h", lineno=541, op=0x7ffff79e8fb0) at /usr/include/python3.8/object.h:478
#6  0x00007ffff794a11e in _Py_XDECREF (op=0x7ffff79e8fb0) at /usr/include/python3.8/object.h:541
#7  0x00007ffff794a6eb in pybind11::handle::dec_ref() const & (this=0x7ffff68ce5e0) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/pytypes.h:199
#8  0x00007ffff794a7b2 in pybind11::object::~object (this=0x7ffff68ce5e0, __in_chrg=<optimized out>) at /usr/local/lib/python3.8/dist-packages/pybind11/include/pybind11/pytypes.h:242
#9  0x00007ffff7948a9d in CoreScanner::OnBarcodeEvent (this=0x9aed90, eventType=0,
    pscanData="<outArgs\000<scannerID\000\061\000/scannerID><arg-xml\000<scandata\000<modelnumber\000DS2208-SR00007ZZWW\000/modelnumber><serialnumber\000\062\060\062\061\066\060\061\060\065\065\060\070\070\063  \000/serialnumber><GUID\000F6041394E2C0499E8DE4625340FC109A\000/GUID><datatype\000\063\000/"...) at /home/scanner-worker/zebra-scanner/src/BoostPythonCoreScanner.cpp:469
#10 0x00007ffff76e6197 in EventListenerXmlImpl::OnBarcodeEvent(int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned char*, int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&) () from /usr/lib/zebra-scanner/corescanner/libcs-client.so
#11 0x00007ffff76aa4f9 in ?? () from /usr/lib/zebra-scanner/corescanner/libcs-client.so
#12 0x00007ffff76bf81d in boost::detail::thread_data<void (*)()>::run() () from /usr/lib/zebra-scanner/corescanner/libcs-client.so
#13 0x00007ffff76f1c3d in ?? () from /usr/lib/zebra-scanner/corescanner/libcs-client.so
#14 0x00007ffff7db5609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#15 0x00007ffff7ef1293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

[andrewshvv]

@dayjaby Moving to pybind11==2.5.0 from 2.6.1 resolved the issue!! 🎊

pip3 install pybind11==2.5.0

[andrewshvv]

Probably README has to mention that there might be troubles with 2.6.1 version, it might help others to avoid the issue.

[mcyenikoylu]

Hey @andrewshvv Thank you for your sharing. I have a system similar to yours. MacOS Ventura 13.2 (22D49) + VirtualBox 7.0 + Windows 10 PRO Zebra DS2208 Barcode Scanner does not recognize my device. Developer SDK tools installed. Other than that, is there any software or driver I need to install?