Tag Archives: debug

[Solved] Vue2.x vue-lazyload Error: Failed to resolve directive: lazy

Today, I want to realize the lazy loading of pictures. After registering components according to the tutorial, the console will report an error as above

The version in package.json is found to be the default downloaded version 3.0.0-rc.2

Solution:

Try to modify the version to 1.3.3

"dependencies": {
    "axios": "^0.27.2",
    "core-js": "^3.8.3",
    "element-ui": "^2.15.9",
    "vue-lazyload": "^1.3.3",
    "vue": "^2.6.14",
    "vue-router": "^3.1.3"
  },

Run, no more errors!

[Solved] RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-singleton dim

Error Messages:
tensor.sub_(mean[:, None, None]).div_(std[:, None, None])
RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-singleton dimension 0

Error Reason:
Dimensional information mismatch

Original Code:

image = Image.open(image_path)

After modification:

image = Image.open(image_path).convert('RGB')

How to Solve MacOS ffmpeg killed Error


tags: MacOS Debug Tips

Question

Recently, I wanted to download the live playback course in nailing with the tried and true method, but some errors suddenly appeared when executing ffmpeg on the command line:

[1]    40344 killed     ffmpeg

 

Solution:

This problem can be solved by compiling and installing from the source code through the following command

brew tap homebrew-ffmpeg/ffmpeg
brew install homebrew-ffmpeg/ffmpeg/ffmpeg

At this time, enter ffmpeg in the terminal to get:

❯ ffmpeg
ffmpeg version 5.0 Copyright (c) 2000-2022 the FFmpeg developers
  built with Apple clang version 13.1.6 (clang-1316.0.21.2)
  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/5.0-with-options_2 --enable-shared --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libaom --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-libsnappy --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-demuxer=dash --enable-opencl --enable-videotoolbox --enable-neon --disable-htmlpages
  libavutil      57. 17.100/57. 17.100
  libavcodec     59. 18.100/59. 18.100
  libavformat    59. 16.100/59. 16.100
  libavdevice    59.  4.100/59.  4.100
  libavfilter     8. 24.100/ 8. 24.100
  libswscale      6.  4.100/ 6.  4.100
  libswresample   4.  3.100/ 4.  3.100
  libpostproc    56.  3.100/56.  3.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

How to Solev PyEddyTracker geostrophic current calculation Error

Error message

Call add_uv_lagerloef() function in pyEddyTracker==3.5.0  reports an error:

numba.core.errors.TypingError: Failed in nopython mode pipeline (step: nopython frontend)
No implementation of function Function(<built-in function sub>) found for signature:
 
 >>> sub(UniTuple(int64 x 2), float64)
 
There are 12 candidate implementations:
   - Of which 10 did not match due to:
   Overload of function 'sub': File: <numerous>: Line N/A.
     With argument(s): '(UniTuple(int64 x 2), float64)':
    No match.
   - Of which 2 did not match due to:
   Operator Overload in function 'sub': File: unknown: Line unknown.
     With argument(s): '(UniTuple(int64 x 2), float64)':
    No match for registered cases:
     * (int64, int64) -> int64
     * (int64, uint64) -> int64
     * (uint64, int64) -> int64
     * (uint64, uint64) -> uint64
     * (float32, float32) -> float32
     * (float64, float64) -> float64
     * (complex64, complex64) -> complex64
     * (complex128, complex128) -> complex128
During: typing of intrinsic-call at D:\Miniconda3\envs\dl\lib\site-packages\py_eddy_tracker\generic.py (570)
File "D:\Miniconda3\envs\dl\lib\site-packages\py_eddy_tracker\generic.py", line 570:
def nearest_grd_indice(x, y, x0, y0, xstep, ystep):
    <source elided>
    return (
        numba_types.int32(round(((x - x0[0]) % 360.0)/xstep)),
        ^
python-BaseException
Backend TkAgg is interactive backend. Turning interactive mode on.

Temporary Solution:
Find add_uv_lagerloef() function in ~/.conda/envs/dl/lib/python3.7/site-packages/py_eddy_tracker/dataset/grid.py line 1700:
Modify:

    def add_uv_lagerloef(self, grid_height, uname="u", vname="v", schema=15):
        self.add_uv(grid_height, uname, vname)
        latmax = 5
        # _, (i_start, i_end) = self.nearest_grd_indice((0, 0), )
        i_start, i_end = (((-latmax, latmax) - self.y_bounds[0])/self.ystep).round().astype('int32')  # debug from numba
        sl = slice(i_start, i_end)
        # Divide by sideral day
        lat = self.y_c[sl]
        gob = (
            cos(deg2rad(lat))
            * ones((self.x_c.shape[0], 1))
            * 4.0
            * pi
           /(23 * 3600 + 56 * 60 + 4.1)
           /self.EARTH_RADIUS
        )
        with errstate(divide="ignore"):
            gob = self.GRAVITY/(gob * ones((self.x_c.shape[0], 1)))
        mode = "wrap" if self.is_circular() else "reflect"

        # fill data to compute a finite difference on all point
        data = self.convolve_filter_with_dynamic_kernel(
            grid_height,
            self.kernel_bessel,
            lat_max=10,
            wave_length=500,
            order=1,
            extend=0.1,
        )
        data = self.convolve_filter_with_dynamic_kernel(
            data, self.kernel_bessel, lat_max=10, wave_length=500, order=1, extend=0.1
        )
        data = self.convolve_filter_with_dynamic_kernel(
            data, self.kernel_bessel, lat_max=10, wave_length=500, order=1, extend=0.1
        )
        v_lagerloef = (
            self.compute_finite_difference(
                self.compute_finite_difference(data, mode=mode, schema=schema),
                mode=mode,
                schema=schema,
            )[:, sl]
            * gob
        )
        # u_lagerloef = (
        #     -self.compute_finite_difference(
        #         self.compute_finite_difference(data, vertical=True, schema=schema),
        #         vertical=True,
        #         schema=schema,
        #     )[:, sl]
        #     * gob
        # )
        u_lagerloef = (
            -self.compute_finite_difference(
                self.compute_finite_difference(data, mode=mode, schema=schema),
                mode=mode,
                schema=schema,
            )[:, sl]
            * gob
        )
        w = 1 - exp(-((lat/2.2) ** 2))
        self.vars[vname][:, sl] = self.vars[vname][:, sl] * w + v_lagerloef * (1 - w)
        self.vars[uname][:, sl] = self.vars[uname][:, sl] * w + u_lagerloef * (1 - w)

1 line 1703Don’t use numba to calculate i_start, i_end

	# _, (i_start, i_end) = self.nearest_grd_indice((0, 0), )
	i_start, i_end = (((-latmax, latmax) - self.y_bounds[0])/self.ystep).round().astype('int32')

2 line 1743 fix the problem that the generated ugos is missing

        # u_lagerloef = (
        #     -self.compute_finite_difference(
        #         self.compute_finite_difference(data, vertical=True, schema=schema),
        #         vertical=True,
        #         schema=schema,
        #     )[:, sl]
        #     * gob
        # )
        u_lagerloef = (
            -self.compute_finite_difference(
                self.compute_finite_difference(data, mode=mode, schema=schema),
                mode=mode,
                schema=schema,
            )[:, sl]
            * gob
        )

[Solved] C++ Compile Error: prerequisites are different [How to Solve]

Scene

When adding new x.h/x.hpp/X.C/x.cpp files to the UE4 project, even if there are no other files to include these new files, the following errors may appear during compilation (both build and rebuild):
unrealbuildtool prerequisites are different
this error occurs when the x.obj file is compiled, but the link operation cannot be performed correctly

reason

As the name suggests, there is no problem with the code itself, but that the code block cannot be integrated into the existing project. UE4 has preprocessing on the path for the include file. If the path name of the file is duplicate, this problem will occur. For example:

1. Proto/error.pb.h already exists under module 

2. try to add Server/XXServer/proto/error.pb.h

According to the include rule of UE4, #include "proto/error.Pb.H" may point to two files at the same time (when the files in the server/xxserver directory are imported), so it cannot be judged accurately, and an error is reported during compilation.

Note: unrealbuildtool under Windows does not judge case, and the paths of proto/and proto/are the same

Solution:

    directory paths should not overlap. Try to avoid the path with the same name.
    1. There should be no files with the same name under the path

 

[Solved] original_keras_version = f.attrs[‘keras_version‘].decode(‘utf8‘)

windows system:
original_keras_version = f.attrs[‘keras_version’].decode(‘utf8’)
1. error:

load_weights_from_hdf5_group
    original_keras_version = f.attrs['keras_version'].decode('utf8')

AttributeError: 'str' object has no attribute 'decode'

2. Cause analysis

When installing tensorflow, the default installed h5py is 3.1.0, and an error is reported because the TF you installed does not support an excessively high version of h5py

3. Solutions

1. Uninstall h5py3 Version 1.0, installing h5py2.0 Version 10.0.2. Restart the compiler

pip install h5py==2.10.0

[Solved] “error_code“:500,“message“:“IO Error trying to forward REST request: java.net.ConnectException: Connection Refused

“error_code”:500,“message”:“IO Error trying to forward REST request: java.net.ConnectException: Connection refused”
An error is reported by executing the following command.
curl -u debezium:4a3s4d02234 http://debezium-001.optics.net:8083/connectors/mysql-optics-prod/restart -X POST
The error message is shown below.
{“error_code”:500, “message”: “IO Error trying to forward REST request: java. ConnectException: Connection refused”}
Solution: make sure the following parameters are set correctly.
rest.host.name=debezium-001.optics.netrest.port=8083

[Solved] PYNQ load bit error: KeyError: ‘interrupts‘

Problem Description:

In the BD diagram of vivado, the interrupted direct connection between my IP and PS Core

An error occurs when loading the bit file generated by vivado in pynq

Solution:

Add a concat block in the connection between PS and our own IP interrupt line, as shown in the figure below

finally, the bit file can be successfully loaded in pynq

and the final program can output correct results

[Solved] Error creating bean with name ’emf’ defined in org.ngrinder.infra.config.DatabaseConf

This similar problem has been encountered several times, but you can still find the error every time you report an error. When reporting an error, think about what you modified earlier, and then go to see if the corresponding code has the same path. Or attribute problems. But I can’t find the error report this time. The previous version before my modification can still be started. When I came to work the next day, I reported an error as soon as it was started. It has not been solved yet. If it is solved, the answer will be pasted. The following error reasons:

Code text:

01-Dec-2021 18:58:11.804 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Spring WebApplicationInitializers detected on classpath: [org.springframework.boot.autoconfigure[email protected]b0ebd27]
01-Dec-2021 18:58:11.953 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Initializing Spring root WebApplicationContext
01-Dec-2021 18:58:15.892 严重 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.StandardContext.listenerStart 异常将上下文初始化事件发送到类的侦听器实例.[org.springframework.web.context.ContextLoaderListener]
		at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:470)
		at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:424)
		at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:310)
		at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:319)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
		... 59 more
01-Dec-2021 18:58:15.911 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Closing Spring root WebApplicationContext
	org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'emf' defined in org.ngrinder.infra.config.DatabaseConfig: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Conflicting persistence unit definitions for name 'ngrinder': file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/lib/ngrinder-controller-3.4.4.jar, file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/classes
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
		at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
		at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
		at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
		at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
		at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1054)
		at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:829)
		at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
		at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
		at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
		at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
		at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4763)
		at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5232)
		at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
		at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:755)
		at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:729)
		at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:695)
		at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1775)
		at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
		at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
		at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
		at java.lang.reflect.Method.invoke(Method.java:498)
		at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:291)
		at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
		at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
		at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:483)
		at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
		at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
		at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
		at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
		at java.lang.reflect.Method.invoke(Method.java:498)
		at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:291)
		at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
		at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
		at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
		at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
		at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
		at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
		at java.security.AccessController.doPrivileged(Native Method)
		at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408)
		at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
		at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
		at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
		at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
		at java.lang.reflect.Method.invoke(Method.java:498)
		at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
		at sun.rmi.transport.Transport$1.run(Transport.java:200)
		at sun.rmi.transport.Transport$1.run(Transport.java:197)
		at java.security.AccessController.doPrivileged(Native Method)
		at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
		at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
		at java.security.AccessController.doPrivileged(Native Method)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
		at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
		at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
		at java.lang.Thread.run(Thread.java:748)
	Caused by: java.lang.IllegalStateException: Conflicting persistence unit definitions for name 'ngrinder': file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/lib/ngrinder-controller-3.4.4.jar, file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/classes

The problem has been solved. Let’s talk about my handling method. I won’t talk about bullshit. I’ve met those interfaces with the same URL, no annotation, the same method name, wrong package, different versions, repeated POM files or inconsistent versions, and what reset projects empty Maven and download again. I’ve met them many times, I’ve tried it all. The answers on the Internet are the same, copy around. My situation is like this. I can run on the first day, but I can’t do it on the second day. I don’t have a clue about the error reported. I checked the GIT code again and again and found that there is nothing wrong and I can’t start. So I did the following work:

1. Find the local tomcat, delete the jar package in webapp and the compiled project file, delete the Tomcat configuration in the project, and reconfigure it

2. Check whether Maven is configured correctly, whether Maven is its own, whether the settings.xml file is correct, and the warehouse. There are many local versions of tomcat, Maven and JDK. I downloaded a lot to test the difference between versions before. After checking, click the navigation bar on the right, circle, refresh and brush several times

3. Click File >>>> ProjectStructure>>> Modules, delete all and reintroduce

4. Check whether the artifacts are correct, and there must be all of them

5. On the right navigation bar, refresh maven, clear, complex, package and run, which solves my problem.

The above is my solution. I have no problem with the code. If there is a problem with the code, don’t use it

RuntimeError: CUDA out of memory. Tried to allocate 600.00 MiB (GPU 0; 23.69 GiB total capacity)

RuntimeError: CUDA out of memory. Tried to allocate 600.00 MiB (GPU 0; 23.69 GiB total capacity; 21.82 GiB already allocated; 115.25 MiB free; 21.87 GiB reserved in total by PyTorch)

Runtime error: CUDA out of memory. Attempt to allocate 600.00 MIB (GPU 0; 23.69 gib total capacity; 21.82 gib allocated; 115.25 MIB free; pytorch reserves a total of 21.87 GIB)

reason

A similar bug is due to insufficient video memory

Solution 1: release the video memory

First fuser - V/dev/NVIDIA * or sudo fuser - V/dev/NVIDIA * , view the processes running on the GPU recently, and then sudo kill the relevant process number.

Of which:

Fuser: it can display which program is currently using a file, mount point, or even network port on the disk, and give the details of the program process – V: detailed mode/dev/NVIDIA *: all NVIDIA related interfaces (such as GPU)

Solution 2: turn down the batch size

If it is not enough after releasing part of the video memory, you can reduce the batch size


Reference:
after NVIDIA GPU kill process, the video memory is still unclear

[Solved] Ubuntu Terminal Error: subprocess installed post-installation script returned error exit status 1

An error occurred in the ubuntu terminal:subprocess installed post-installation script returned error exit status 1
An error occurred in the ubuntu terminal:subprocess installed post-installation script returned error exit status 1

An error occurred in the ubuntu terminal:subprocess installed post-installation script returned error exit status 1

System: Ubuntu 16.04

Error:

Use Command cd /sur/bin/dpkg/info

Folder usage: ls | grep ubuntu-advantage-tools*

The command to find the file with the error uses:sudo rm ubuntu-advantage-tools*
Delete is OK!

RuntimeError: cuda runtime error (801) : operation not supported at ..

error message

THCudaCheck FAIL file=..\torch/csrc/THCudaChgeneck FAeric/StoragITHL Cuefile=Sha.da.\rCinhtoregcch.k cpp /csrcline=24F/gAI9 errL file=oe..\tor=nr801 : eoric/Stopch/ceration not susrcpporte/gend
eric/StorageSharing.cpp rageSharing.cpp line=249 error=801 : operation not supported
line=249 error=801 : operation not supported
Traceback (most recent call last):
Traceback (most recent call last):
  File "D:\Miniconda3\envs\dl\lib\multiprocessing\queues.py", line 236, in _feed
    obj = _ForkingPickler.dumps(obj)
  File "D:\Miniconda3\envs\dl\lib\multiprocessing\reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
  File "D:\Miniconda3\envs\dl\lib\multiprocessing\queues.py", line 236, in _feed
    obj = _ForkingPickler.dumps(obj)
  File "D:\Miniconda3\envs\dl\lib\site-packages\torch\multiprocessing\reductions.py", line 247, in reduce_tensor
    event_sync_required) = storage._share_cuda_()
  File "D:\Miniconda3\envs\dl\lib\multiprocessing\reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
Traceback (most recent call last):
  File "D:\Miniconda3\envs\dl\lib\site-packages\torch\multiprocessing\reductions.py", line 247, in reduce_tensor
    event_sync_required) = storage._share_cuda_()
RuntimeError: cuda runtime error (801) : operation not supported at ..\torch/csrc/generic/StorageSharing.cpp:249
RuntimeError: cuda runtime error (801) : operation not supported at ..\torch/csrc/generic/StorageSharing.cpp:249

reason

https://github.com/fastai/fastbook/issues/85

Since pytorch multiprocessing does not work on windows, set the num of dataloaders_ workers=0