Category Archives: Operating Systems

How I built QT 5.11.1 for Android on Windows

I tried to build QT 5.11.1 for Android on Windows, and “configure.bat” completed successfully, but “mingw32-make” failed with with the following error:

No rule to make target 'vulkan/qvulkanfunctions_p.h', needed by '.obj\qvulkaninstance.obj'.

It is the bug fixed in QT 5.11.2 that is planned on August/September 2018.

When I build the master branch and copied the following files from it to \qtbase\src\gui\vulkan manually:


and started “mingw32-make” again I got another error:


Mining Ethereum on Ubuntu 18.04 with GeForce GTX 1060 3GB

I am not a Linux expert, so it took me some time to configure my mining rig on Ubuntu 18.04 with NVIDIA GeForce GTX 1060 3GB, and I wrote down all the steps I did:

First I installed NVIDIA driver, but OpenCL did not install automatically with it and I installed it manually with the following command:

sudo apt install -y ocl-icd-libopencl1

Then I installed CURL:

sudo apt install -y libcurl3

not ‘curl’ and not ‘libcurl4’ packages, otherwise the miner will fail to start reporting the following error message:

./ethdcrminer64: /usr/lib/x86_64-linux-gnu/ version `CURL_OPENSSL_3' not found (required by ./ethdcrminer64)


PHP script that saves client IP address to a file.

Below I wrote down a simple PHP script that saves client IP address to a file. If the IP address of your home machine periodically changes, you can store it on a web server once a minute by scheduling a task like this:

sudo crontab -u <user> -e
* * * * * wget -q -O /dev/null -o /dev/null ""

where ip.php is the following PHP script:

Multiple versions of Microsoft.Web.Administration.dll in IIS 10

On some Windows 10 machine with IIS 10 installed I have three Microsoft.Web.Administration.dll:

Two versions and in GAC (C:\Windows\assembly\GAC_MSIL\Microsoft.Web.Administration\) in and folders respectively and one version in C:\Windows\System32\inetsrv\.

The following XML element in a Visual Studio project file adds a reference to version of Microsoft.Web.Administration.dll:

<Reference Include="Microsoft.Web.Administration, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">

The same XML element with SpecificVersion=False will automatically reference the highest available version on this machine that is


Setting up QT Creator 4.6.1 for Android development on Windows 10

First I installed Android Studio. When it started I set an option to create the application with Native C++ support and Android NDK was automatically installed to C:\Users\AppData\Local\Android\Sdk\ndk-bundle, also I added Android-19 API level and somehow CMake was installed to C:\Users\AppData\Local\Android\Sdk\cmake\3.6.4111459. Then in QT Creator I opened Tools->Options->Devices->Android and specified the following paths:


Building QT 5.10.1 from sources with VS2017

I am not sure it is a correct way, but I was able to do this:

git clone --recursive --branch v5.10.1

and all the submodules were checked out with commit hashes tag v5.10.1 points to:

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.
Submodule path 'qt3d': checked out '31f424bb81cd2583920d3d521e1e01f01c2d28e2'


How to remove APPX package installed by another user.

There is new option ‘-AllUsers’ in Windows 10 1709 so ‘LinesGame’ APPX package, for example, can be removed for all users with the following command:

Get-AppxPackage -all *lines*
Get-AppxPackage -all *lines* | Remove-AppxPackage -AllUsers

the first line outputs this:

Name                   : 48696GeoGraphX.Lines3D
Publisher              : CN=4596C2AF-8F16-46B2-976A-1D49B97B0C80
Architecture           : X64
ResourceId             :
Version                :
PackageFullName        : 48696GeoGraphX.Lines3D_2.0.109.0_x64__rc9z1pmca2qa0
InstallLocation        :
IsFramework            : False
PackageFamilyName      : 48696GeoGraphX.Lines3D_rc9z1pmca2qa0
PublisherId            : rc9z1pmca2qa0
PackageUserInformation : {S-1-5-21-1513020516-1447999005-958985207-1001
                         [S-1-5-21-1513020516-1447999005-958985207-1001]: Installed}
IsResourcePackage      : False
IsBundle               : False
IsDevelopmentMode      : True
IsPartiallyStaged      : False
SignatureKind          : None
Status                 : Ok

Built-in utility for calculating MD5 and SHA1 checksums in Windows 10

To calculate MD5 checksum of a file in Windows 10 open a command prompt and run the following command:

certutil -hashfile <path to the file> MD5

to calculate SHA1 replace MD5 parameter used above with SHA1:

certutil -hashfile <path to the file> SHA1

The possible values of this parameter are: MD2, MD4, MD5, SHA1, SHA256, SHA384, SHA512

ASUS H270M-PLUS Motherboard requires specific network driver for Windows 10.

Windows 10 does not find network driver for ASUS H270M-PLUS motherboard automatically and the driver supplied with the motherboard does not install showing the message “The Realtech network controller was not found. If deep sleep mode is enabled please plug the cable”. But there is some specific Intel(R) Ethernet Connection (2) I219-V driver that works fine:

It is no more possible to mine Ethereum using 3GB graphic card on Windows 10

I mistakenly believed that 3GB of video memory is enough for mining, while EthDcrMiner64.exe does not work with 3GB on Windows 10 and reports the following errors:

Setting DAG epoch #180 for GPU0
Create GPU buffer for GPU0
ETH: 04/08/18-06:19:23 – New job from
ETH – Total Speed: 0.000 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:00
ETH: GPU0 0.000 Mh/s
CUDA error – cannot allocate big buffer for DAG. Check readme.txt for possible solutions.
ETH: 04/08/18-06:19:25 – New job from
ETH – Total Speed: 0.000 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:00
ETH: GPU0 0.000 Mh/s
Setting DAG epoch #180 for GPU0
GPU 0, CUDA error 11 – cannot write buffer for DAG