Tag: error

Warning: Can’t call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method. – ReactJs

Hi everyone,

This is just a quick post, mostly for my future reference but hopefully it will help someone else out as well. I ran into the following error when invoking a callback in a child component:

Warning: Can't call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.

This is generally a result of updating the state of a child component after the parent component has hidden it.

e.g. the child component calls a prop function which hides the child component. On the line after the prop function call the child component attempts to set a state variable.

Issue

In my case, it was because I was setting the loading state of a child component to false after performing a successful fetch. Normally this would be fine however I had hidden the child component via the parent component’s prop callback after the successful response was confirmed.

  • (Child Component): Set loading state to true.
  • (Child Component): Call API
  • (Child Component): After retrieving payload, invoke parent component’s prop function and pass it the payload
  • (Parent Component): Process payload. In render, the new payload hides the child component
  • (Child Component): Attempts to set loading state to false Error: can’t change state now that the component is no longer mounted

Solution

To get around it, I had to ensure that I didn’t invoke the parent’s callback (or unload the child) until after the child’s state had been set.

  • (Child Component): Set loading state to true.
  • (Child Component): Call API
  • (Child Component): Retrieve payload, set loading state to false place state change before parent callback is invoked
  • (Child Component): Invoke parent component’s prop function and pass it the payload
  • (Parent Component): Process payload. In render, the new payload hides the child component

Now that the child component state is modified before it is unmounted there isn’t an issue. The easiest way that I’ve found to debug errors like this is to set breakpoints (either hardcoded or in the console) to ensure that everything is being invoked in the expected order.

If you need any more info please let me know!

Thanks,
Chris

Module build failed: Error: ENOENT: no such file or directory, open – Windows

Hi everyone,

I’ve been mucking around with React over the last couple of days. I ran into the following error while trying to build:

Module build failed: Error: ENOENT: no such file or directory, open ‘c:…Form.js’
at Error (native)

It took a while to sort this one out but I eventually came across a solution on github:

npm rebuild node-sass

Thanks to xzyfer for posting in the following github thread: https://github.com/sass/node-sass/issues/1579#issuecomment-227661284

There’s a whole heap of info in that thread so be sure to check it out.

Thanks,
Chris

Cannot attach the file ‘C:…database.mdf’ as database x – Entity Framework

Hi everyone,

I ran into the following error when attempting to run ‘update-database’ on an initial migration:

Cannot attach the file ‘C:Users…App_Dataaspnet-…115933.mdf’ as database ‘aspnet-…15933’

The solution to this one is pretty easy, remove the initial catalog property from your connection string.

…33.mdf;Initial Catalog=aspnet…

This is apparently caused by issues with EntityFramework and multiple projects in the same database. See the following stackoverflow answer for more info: https://stackoverflow.com/a/20176660/522859

Unsupported_Grant_Type – MVC Web Api (error)

Hi everyone,

I ran into the following error while attempting to authenticate using .NET Web Api:

POST http://localhost:63720/Token HTTP/1.1
Host: localhost:63720
Content-Type: application/json
Content-Length: 0
HTTP/1.1 400 Bad Request
Content-Type: application/json;charset=UTF-8
Date: Mon, 16 Apr 2018 14:18:06 GMT
Content-Length: 34

{“error”:”unsupported_grant_type”}

This one was pretty straight forward. Ensure that have the correct content-type:

Content-Type: application/x-www-form-urlencoded

And finally, ensure that you provide a grant type in the request body:

grant_type=password&username=test_username&password=test_password

Thanks to the following stackoverflow post for the info: https://stackoverflow.com/a/29261024/522859

An error occurred (UnrecognizedClientException) when calling the CreateFunction operation: The security token included in the request is invalid.

Hi everyone,

I ran into the following error today while attempting to create a Lambda function using the CLI:

An error occurred (UnrecognizedClientException) when calling the CreateFunction operation: The security token included in the request is invalid.

The first thing to check is that your aws config is setup correctly. For me this is under c:userschris-pc.aws.

If that looks fine, double check that the associated user has the correct rights by viewing the IAM page in the server console: https://console.aws.amazon.com/iam/home

Finally, ensure that the user has programmatic access and that the keys match those in your config.

FAILED. Reason: Requires capabilities : [CAPABILITY_IAM] – AWS SAM

Hi everyone,

I ran into an error today while trying to deploy using AWS SAM:

aws cloudformation deploy –template-file C:Usersxxxserverless-output.yaml –stack-name events-app
Failed to create the changeset: Waiter ChangeSetCreateComplete failed: Waiter encountered a terminal failure state Status: FAILED. Reason: Requires capabilities : [CAPABILITY_IAM]

The solution is pretty straightforward. You need to explicitly add –capabilities CAPABILITY_IAM to you command:

Serverless Offline Error – sls offline start

Hi everyone,

I ran into the following error while trying to start serverless offline:

serverles events.js:160
throw er Unhandled ‘error’ event spawn java ENOENT at exports._errnoException (util.js:1020:11) at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32) at onErrorNT (internal/child_process.js:376:16) at _combinedTickCallback (internal/process/next_tick.js:80:11) at process._tickDomainCallback (internal/process/next_tick.js:128:9)

Solution
It turned out to be because I didn’t have the Java JDK installed.

I expect you’ll have the same problem if the command prompt doesn’t have access to the JAVA_HOME variable or if your JAVA_HOME path isn’t set correctly.

AttributeError: module ‘serial’ has no attribute ‘SerialException’ – Python 3.5

Hi everyone,

A quick fix for an error I ran into while updating to Pyhton 3.5.2:

AttributeError: module 'serial' has no attribute 'SerialException'

I needed to add pyserial:

pi@raspberrypi:~/Desktop/piscripts/get-commands $ sudo pip3.5 install pyserial
Collecting pyserial
  Downloading pyserial-3.4-py2.py3-none-any.whl (193kB)
    100% |████████████████████████████████| 194kB 530kB/s
Installing collected packages: pyserial
Successfully installed pyserial-3.4

Thanks to the following link: https://stackoverflow.com/a/47562659/522859

Could not find a version that satisfied the requirement smbus/python3-smbus

Hi everyone,

I ran into a bit of an issue installing smbus on Python3.5. It looks like all you have to do is use smbus2:

pip3.5 install smbus2

Collecting smbus2
Downloading smbus2-0.2.0.tar.gz
Building wheels for collected packages: smbus2
Running setup.py bdist_wheel for smbus2 … done
Stored in directory: /root/.cache/pip/wheels/90/71/b4/9f90d8e2d0349ab55fef07169a81bd8f925965f16174e2f809
Successfully built smbus2
Installing collected packages: smbus2
Successfully installed smbus2-0.2.0

Thanks to the following link: https://www.raspberrypi.org/forums/viewtopic.php?t=192909

Pillow Install Fails – Python 3.5.2

Hi everyone,

Pillow install fails

I ran into a bit of an issue trying to install Pillow on Raspbian with Python 3.5.2. The full error is below, but the solution was simply to install the following:

sudo apt-get install libjpeg8-dev
sudo pip3.5 install pillow

sudo pip3.5 install pillow
Collecting pillow
Using cached Pillow-4.3.0.tar.gz
Requirement already satisfied: olefile in /usr/local/lib/python3.5/site-packages (from pillow)
Installing collected packages: pillow
Running setup.py install for pillow … error
Complete output from command /usr/local/bin/python3.5 -u -c “import setuptools, tokenize;__file__=’/tmp/pip-build-inj0l_9q/pillow/setup.py’;f=getattr(tokenize, ‘open’, open)(__file__);code=f.read().replace(‘rn’, ‘n’);f.close();exec(compile(code, __file__, ‘exec’))” install –record /tmp/pip-xp_x4w_5-record/install-record.txt –single-version-externally-managed –compile:
running install
running build
running build_py
creating build
creating build/lib.linux-armv7l-3.5
creating build/lib.linux-armv7l-3.5/PIL
copying PIL/MicImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageMath.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/WebPImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImagePath.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageGrab.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/SunImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/__init__.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageEnhance.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageMorph.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/XpmImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/EpsImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/FtexImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/WmfImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/FitsStubImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageDraw2.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/IptcImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/_binary.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/MpoImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/Hdf5StubImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/Image.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/MspImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageWin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GimpPaletteFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageTk.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PSDraw.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/McIdasImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/SgiImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageStat.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageChops.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PdfImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/features.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PcfFontFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PcxImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageOps.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImagePalette.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/TgaImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageSequence.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/_util.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/TiffTags.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/BmpImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/DdsImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ExifTags.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PyAccess.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PpmImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageCms.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PaletteFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/XVThumbImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/IcoImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageFilter.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageFont.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GifImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GbrImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/XbmImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PngImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/FontFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/IcnsImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/TiffImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/_tkinter_finder.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/DcxImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/OleFileIO.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/SpiderImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/JpegImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GribStubImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/MpegImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PalmImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/BdfFontFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GimpGradientFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PsdImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/WalImageFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PcdImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/version.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/FpxImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageQt.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/Jpeg2KImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageDraw.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/GdImageFile.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ContainerIO.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/CurImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/FliImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageMode.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/JpegPresets.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/PixarImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageColor.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/BufrStubImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageTransform.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImageShow.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/TarIO.py -> build/lib.linux-armv7l-3.5/PIL
copying PIL/ImtImagePlugin.py -> build/lib.linux-armv7l-3.5/PIL
running egg_info
writing dependency_links to Pillow.egg-info/dependency_links.txt
writing requirements to Pillow.egg-info/requires.txt
writing top-level names to Pillow.egg-info/top_level.txt
writing Pillow.egg-info/PKG-INFO
warning: manifest_maker: standard file ‘-c’ not found

reading manifest file ‘Pillow.egg-info/SOURCES.txt’
reading manifest template ‘MANIFEST.in’
warning: no files found matching ‘*.sh’
no previously-included directories found matching ‘docs/_static’
warning: no previously-included files found matching ‘.coveragerc’
warning: no previously-included files found matching ‘codecov.yml’
warning: no previously-included files found matching ‘.editorconfig’
warning: no previously-included files found matching ‘.landscape.yaml’
warning: no previously-included files found matching ‘.travis’
warning: no previously-included files found matching ‘.travis/*’
warning: no previously-included files found matching ‘appveyor.yml’
warning: no previously-included files found matching ‘build_children.sh’
warning: no previously-included files found matching ‘tox.ini’
warning: no previously-included files matching ‘.git*’ found anywhere in distribution
warning: no previously-included files matching ‘*.pyc’ found anywhere in distribution
warning: no previously-included files matching ‘*.so’ found anywhere in distribution
writing manifest file ‘Pillow.egg-info/SOURCES.txt’
running build_ext

The headers or library files could not be found for jpeg,
a required dependency when compiling Pillow from source.

Please see the install instructions at:
https://pillow.readthedocs.io/en/latest/installation.html

Traceback (most recent call last):
File “/tmp/pip-build-inj0l_9q/pillow/setup.py”, line 787, in
zip_safe=not (debug_build() or PLATFORM_MINGW), )
File “/usr/local/lib/python3.5/distutils/core.py”, line 148, in setup
dist.run_commands()
File “/usr/local/lib/python3.5/distutils/dist.py”, line 955, in run_commands
self.run_command(cmd)
File “/usr/local/lib/python3.5/distutils/dist.py”, line 974, in run_command
cmd_obj.run()
File “/usr/local/lib/python3.5/site-packages/setuptools/command/install.py”, line 61, in run
return orig.install.run(self)
File “/usr/local/lib/python3.5/distutils/command/install.py”, line 539, in run
self.run_command(‘build’)
File “/usr/local/lib/python3.5/distutils/cmd.py”, line 313, in run_command
self.distribution.run_command(command)
File “/usr/local/lib/python3.5/distutils/dist.py”, line 974, in run_command
cmd_obj.run()
File “/usr/local/lib/python3.5/distutils/command/build.py”, line 135, in run
self.run_command(cmd_name)
File “/usr/local/lib/python3.5/distutils/cmd.py”, line 313, in run_command
self.distribution.run_command(command)
File “/usr/local/lib/python3.5/distutils/dist.py”, line 974, in run_command
cmd_obj.run()
File “/usr/local/lib/python3.5/distutils/command/build_ext.py”, line 338, in run
self.build_extensions()
File “/tmp/pip-build-inj0l_9q/pillow/setup.py”, line 577, in build_extensions
raise RequiredDependencyException(f)
__main__.RequiredDependencyException: jpeg

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File “”, line 1, in
File “/tmp/pip-build-inj0l_9q/pillow/setup.py”, line 799, in
raise RequiredDependencyException(msg)
__main__.RequiredDependencyException:

The headers or library files could not be found for jpeg,
a required dependency when compiling Pillow from source.

Please see the install instructions at:
https://pillow.readthedocs.io/en/latest/installation.html

—————————————-
Command “/usr/local/bin/python3.5 -u -c “import setuptools, tokenize;__file__=’/tmp/pip-build-inj0l_9q/pillow/setup.py’;f=getattr(tokenize, ‘open’, open)(__file__);code=f.read().replace(‘rn’, ‘n’);f.close();exec(compile(code, __file__, ‘exec’))” install –record /tmp/pip-xp_x4w_5-record/install-record.txt –single-version-externally-managed –compile” failed with error code 1 in /tmp/pip-build-inj0l_9q/pillow/

Thanks to the comment on the following Stackoverflow post for the solution: https://stackoverflow.com/a/34631976/522859