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Saturday, May 26, 2018

Fedora 28 : Can you fix your Fedora !?

Fedora Packages have a different installation and development process thanks to testing and development teams.
Note: The common user may have networking problems and these will still lead to further errors.
A common error that should be more documented and constrained is:
Error: Failed to synchronize cache for repo 'updates'.

If you did not have intruders in the computer or provider changes to modify this process, then here are some elements that help you understand how it works.
The process of cleanup of temporary files kept for repositories and update / upgrade is still a testing and development process.
This includes any such data left behind from disabled or removed repositories as well as for different distribution release versions.
  • dnf clean dbcache : this removes cache files generated from the repository metadata and forces DNF to regenerate the cache files the next time it is run.
  • dnf clean expire-cache : this marks the repository metadata expired and will re-validate the cache for each repo the next time it is used.
  • dnf clean metadata : just removes repository metadata files which is uses to determine the remote availability of packages and will make to download all the metadata the next time it is run.
  • dnf clean packages :  removes any cached packages from the system.
  • dnf clean all : does all of the above.
You can mix these commands so you can get the desired effect with the shell tool dnf , see this example:
dnf update --refresh
This will make a update but with this feature: --refresh will set metadata as expired before running the command.

Friday, May 25, 2018

Fedora 28 : Video about development and fix packages.

The fedora 28 distribution is an advanced Linux distribution that includes tools and is supported by the fedora community.
The clear and essential reason for the right development is the learning area.
Here's a great video tutorial about developing fedora packets and that's very useful.

I do not know what it is with this group name the Factory 2.0 devel group , but they are very useful information.

Friday, May 11, 2018

Fedora 28 : The LibreCAD application.

LibreCAD - originally CADuntu is a free Open Source CAD application and today I tested with my Fedora 28.
The content for this application is available under Creative Commons Attribution Share Alike. LibreCAD is a free and open-source and can be downloaded from official webpage.
Let's see the install process of this tool:
[root@desk mythcat]# dnf install librecad.x86_64
Last metadata expiration check: 3:00:39 ago on Fri 11 May 2018 07:51:19 PM EEST.
Dependencies resolved.
================================================================================
 Package                  Arch          Version             Repository     Size
================================================================================
Installing:
 librecad                 x86_64        2.1.0-7.fc28        fedora        2.3 M
Installing dependencies:
 libdxfrw                 x86_64        0.6.3-8.fc28        fedora        438 k
 librecad-fonts           noarch        2.1.0-7.fc28        fedora         11 M
 librecad-langs           noarch        2.1.0-7.fc28        fedora        603 k
 librecad-parts           noarch        2.1.0-7.fc28        fedora        903 k
 librecad-patterns        noarch        2.1.0-7.fc28        fedora        217 k
 shapelib                 x86_64        1.4.1-2.fc28        fedora         80 k

Transaction Summary
================================================================================
Install  7 Packages

Total download size: 15 M
Installed size: 109 M
Is this ok [y/N]: y
Downloading Packages:
(1/7): libdxfrw-0.6.3-8.fc28.x86_64.rpm         658 kB/s | 438 kB     00:00    
(2/7): librecad-langs-2.1.0-7.fc28.noarch.rpm   1.4 MB/s | 603 kB     00:00    
(3/7): librecad-2.1.0-7.fc28.x86_64.rpm         1.5 MB/s | 2.3 MB     00:01    
(4/7): librecad-parts-2.1.0-7.fc28.noarch.rpm   1.6 MB/s | 903 kB     00:00    
(5/7): shapelib-1.4.1-2.fc28.x86_64.rpm         1.3 MB/s |  80 kB     00:00    
(6/7): librecad-patterns-2.1.0-7.fc28.noarch.rp 1.3 MB/s | 217 kB     00:00    
(7/7): librecad-fonts-2.1.0-7.fc28.noarch.rpm   3.0 MB/s |  11 MB     00:03    
--------------------------------------------------------------------------------
Total                                           3.5 MB/s |  15 MB     00:04     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : shapelib-1.4.1-2.fc28.x86_64                           1/7 
  Running scriptlet: shapelib-1.4.1-2.fc28.x86_64                           1/7 
  Installing       : librecad-patterns-2.1.0-7.fc28.noarch                  2/7 
  Installing       : librecad-parts-2.1.0-7.fc28.noarch                     3/7 
  Installing       : librecad-langs-2.1.0-7.fc28.noarch                     4/7 
  Installing       : librecad-fonts-2.1.0-7.fc28.noarch                     5/7 
  Installing       : libdxfrw-0.6.3-8.fc28.x86_64                           6/7 
  Running scriptlet: libdxfrw-0.6.3-8.fc28.x86_64                           6/7 
  Installing       : librecad-2.1.0-7.fc28.x86_64                           7/7 
  Running scriptlet: librecad-2.1.0-7.fc28.x86_64                           7/7 
  Verifying        : librecad-2.1.0-7.fc28.x86_64                           1/7 
  Verifying        : libdxfrw-0.6.3-8.fc28.x86_64                           2/7 
  Verifying        : librecad-fonts-2.1.0-7.fc28.noarch                     3/7 
  Verifying        : librecad-langs-2.1.0-7.fc28.noarch                     4/7 
  Verifying        : librecad-parts-2.1.0-7.fc28.noarch                     5/7 
  Verifying        : librecad-patterns-2.1.0-7.fc28.noarch                  6/7 
  Verifying        : shapelib-1.4.1-2.fc28.x86_64                           7/7 

Installed:
  librecad.x86_64 2.1.0-7.fc28          libdxfrw.x86_64 0.6.3-8.fc28            
  librecad-fonts.noarch 2.1.0-7.fc28    librecad-langs.noarch 2.1.0-7.fc28      
  librecad-parts.noarch 2.1.0-7.fc28    librecad-patterns.noarch 2.1.0-7.fc28   
  shapelib.x86_64 1.4.1-2.fc28         

Complete!
I start the application from command shell and this is the output I got.
[mythcat@desk ~]$ librecad 
RS_DEBUG::setLevel(3)
RS_DEBUG: Critical
RS_DEBUG: Errors
RS_DEBUG: Warnings
libpng warning: iCCP: known incorrect sRGB profile
The application works great I don't know from where come the errors.
You can used to test your skills into the area of
The official manual can be found here.
This is a screenshot from my Fedora 28 distro:

Fedora 28 : The Spin tool for 2D animation.

The spine is a 2D skeletal animation tool for your video games.
This tool comes with features to building great looking animations.
Spine exports animation data in its own, documented JSON and binary formats.
You can export animated GIFs, PNG or JPEG image sequences and AVI or QuickTime video.
I install the trial version into my Fedora 28 distro easy.
First, you need to download it and unarchive from the official website.
The next step will start with this command:
[mythcat@desk ~]$ cd SpineTrial/
[mythcat@desk SpineTrial]$ dir
examples  launcher  license.txt  runtimes  scripts  SpineTrial.sh
[mythcat@desk SpineTrial]$ sh SpineTrial.sh 
Spine Launcher 3.6.49 Trial
Linux amd64 4.16.6-302.fc28.x86_64
Java 1.7.0_80 Esoteric Software
64-bit Server VM
Downloading: Spine 3.7.16-beta Trial
Update complete.
Spine 3.7.16-beta Trial
Intel Open Source Technology Center
Mesa DRI Intel(R) Ivybridge Desktop 
3.0 Mesa 18.0.2
Resetting hotkeys (new version).
Using customized hotkeys.
Started.
May 10, 2018 6:54:08 PM java.util.prefs.FileSystemPreferences checkLockFile0ErrorCode
WARNING: Could not lock System prefs. Unix error code 0.
May 10, 2018 6:54:08 PM java.util.prefs.FileSystemPreferences syncWorld
WARNING: Couldn't flush system prefs: java.util.prefs.BackingStoreException: 
Couldn't get file lock.
May 10, 2018 6:54:38 PM java.util.prefs.FileSystemPreferences checkLockFile0ErrorCode
WARNING: Could not lock System prefs. Unix error code 0.
May 10, 2018 6:54:38 PM java.util.prefs.FileSystemPreferences syncWorld
WARNING: Couldn't flush system prefs: java.util.prefs.BackingStoreException: 
Couldn't get file lock
You can some warnings but the tool works great.
More about graphics and Linux design you can find articles on my website.
Look at these screenshots with Spine tool:

Monday, April 23, 2018

Fedora 28 : The OpenShot video editor.

This is a video editor for linux and many operating systems. I tested with Fedora 28 and works good. The install of this is very simple with dnf tool:
# dnf install openshot.noarch
The development team add many features into this software:
Feature list
Cross-platform video editing software (Linux, Mac, and Windows)
Support for many video, audio, and image formats
Powerful curve-based Key frame animations
Desktop integration (drag and drop support)
Unlimited tracks / layers
Clip resizing, scaling, trimming, snapping, rotation, and cutting
Video transitions with real-time previews
Compositing, image overlays, watermarks
Title templates, title creation, sub-titles
3D animated titles (and effects)
Advanced Timeline (including Drag & drop, scrolling, panning, zooming, and snapping)
Frame accuracy (step through each frame of video)
Time-mapping and speed changes on clips (slow/fast, forward/backward, etc...)
Audio mixing and editing
Digital video effects, including brightness, gamma, hue, greyscale, chroma key (bluescreen / greenscreen) , and many more!
The license for this software is this:
License OpenShot™ is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This is a screenshot on my Fedora distro.

Tuesday, April 17, 2018

Fedora 28 : GoLang first example .

This tutorial is about GoLang IDE . About this IDE you can read more here - my intro article about this IDE.
I try to used with the platform-native GUI library for Go named andlabs/ui.
First, after you install the IDE you can check the settings on menu Settings: Using this tool with Fedora 28 is easy.
About the first install of andlabs/ui then this come with this error:
[mythcat@desk ~]$ go get github.com/andlabs/ui
# pkg-config --cflags gtk+-3.0
Package gtk+-3.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtk+-3.0.pc'
to the PKG_CONFIG_PATH environment variable
Package 'gtk+-3.0', required by 'virtual:world', not found
pkg-config: exit status 1
That tell us is need to install some packages from Fedora repo:
# dnf install gtk3-devel
I used this source code to test the andlabs/ui:
package main

import (
   "github.com/andlabs/ui"
)

func main() {
   err := ui.Main(func() {
      input := ui.NewEntry()
      button := ui.NewButton("Greet")
      greeting := ui.NewLabel("")
      box := ui.NewVerticalBox()
      box.Append(ui.NewLabel("Enter your name:"), false)
      box.Append(input, false)
      box.Append(button, false)
      box.Append(greeting, false)
      window := ui.NewWindow("Hello", 200, 100, false)
      window.SetMargined(true)
      window.SetChild(box)
      button.OnClicked(func(*ui.Button) {
         greeting.SetText("Hello, " + input.Text() + "!")
      })
      window.OnClosing(func(*ui.Window) bool {
         ui.Quit()
         return true
      })
      window.Show()
   })
   if err != nil {
      panic(err)
   }
}
First time was run well and after I restart the IDE I got this error:
# gui_test
/usr/lib/golang/pkg/tool/linux_amd64/link: running gcc failed: exit status 1
gcc: error: /home/mythcat/go/src/github.com/andlabs/ui/libui_linux_amd64.a: No such file or directory

The problem come from GoLang IDE settings and andlabs/ui.
I remove and install again the andlabs/ui and now working well.
The result of this source code come with this output:

Saturday, April 14, 2018

Fedora 28 : The VS Code on Fedora.

The Visual Studio Code is an editor for development and includes the features you need for highly productive source code editing.
You can use this editor with many Linux distros.
Today I tested with Fedora 28 distro version.
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
sudo sh -c 'echo -e "[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/
vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc" > /etc/yum.repos.d/vscode.repo'
Then use dnf to check and install this editor.
#dnf check-update
#dnf install code
Next step is to install extensions for Python, Golang, PHP, C# and more.