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Saturday, March 30, 2024

Fedora 41 : Memstrack tool.

A runtime memory allocation tracer, like a hot spot analyzer for memory allocation, can help analyze overall memory usage, peak memory usage, kernel module memory usage, all combined with stacktrace. Userspace memory trace is planned and not yet implemented.
This tool works by tracing all page-level memory allocation events in kernel (currently supports using perf or ftrace), and actively integrate the events into a stack trace tree. It can also work with kernel's page owner log file and use as a memory usage viewer.
I tested this tool today and it is quite useful for development and monitoring the operating system, it seems to work very well, you can even see in the screenshot how ...
You can find this project on the GitHub repo.

Tuesday, March 26, 2024

Fedora 40 : Fix emergency run mode - part 001.

Run this commands to see errors and all failed systemd units:
[root@fedora mythcat]# dmesg | grep err
[root@fedora mythcat]# systemctl status --failed --all
If you get an error like this:
Recovery unable to mount /home
... check the /etc/fstab file to see how your home is set.

Sunday, March 24, 2024

News : Fedora 40 Beta RC 1.10 compose ...

The Fedora Linux 40 Beta RC 1.10 compose is GO and will be shipped live on Tuesday, 26th March 2024.
This announcement was made on the devel-announce list by Aoife Moloney.
Aoife Moloney, the Fedora Operations Architect, has recently joined the Fedora community.
The Beta RC compose serves as a preliminary version of the upcoming Fedora release and allows Quality Engineering (QE) to thoroughly test the system and identify any critical issues before the final release.
You can find schedule for Fedora 40 on the official website.

Friday, March 22, 2024

News : Flutter on Fedora 40 - the run debug info.

The run command comes with info about the running process, see:
[mythcat@fedora examples]$ ../flutter/bin/flutter run
Launching lib/main.dart on Linux in debug mode...
Building Linux application...                                           
Syncing files to device Linux...                                 1,488ms

Flutter run key commands.
r Hot reload. 🔥🔥🔥
R Hot restart.
h List all available interactive commands.
d Detach (terminate "flutter run" but leave application running).
c Clear the screen
q Quit (terminate the application on the device).

A Dart VM Service on Linux is available at: http://127.0.0.1:38903/k8tmzU7n0NQ=/
The Flutter DevTools debugger and profiler on Linux is available at:
http://127.0.0.1:9100?uri=http://127.0.0.1:38903/k8tmzU7n0NQ=/
If you open that URL you will see this type of informations:

Fedora 40 : Spectacle tool.

Spectacle is a screenshot taking utility for the KDE desktop. Spectacle can also be used in non-KDE X11 desktop environments.
This is the GitHub project for this tool.
[root@fedora mythcat]# dnf5 install spectacle.x86_64
Updating and loading repositories:
Repositories loaded.
Package                       Arch   Version                 Repository      Size
Installing:                                                                      
 spectacle                    x86_64 24.02.0-1.fc41          updates-te   4.8 MiB
Installing dependencies:                                                         
...
This is an screenshot with this tool:

Tuesday, March 19, 2024

Fedora 40 : sngrep tool.

The sngrep is a tool for displaying SIP calls message flows from terminal and supports live capture to display realtime SIP packets and can also be used as PCAP viewer.
[mythcat@fedora ~]# dnf copr enable irontec/sngrep
[mythcat@fedora ~]# dnf install sngrep
[mythcat@fedora ~]# exit
[mythcat@fedora ~]$ sudo sngrep  -d ens1 -O save.pcap port 8080 and udp
The result is this:

Sunday, March 17, 2024

News : Flutter on Fedora 40.

Flutter transforms the development process. Build, test, and deploy beautiful mobile, web, desktop, and embedded experiences from a single codebase.
Read more on the official webpage.
Theoretically, Flutter can be used much easier in the Fedora 40 Linux distribution than in a Windows operating system.
The Windows installation method requires more complicated steps with the use of S.D.K. and settings of Android Studio I.D.E. .
Here are the steps you need to follow for a default installation.
[mythcat@fedora ~]$ mkdir ~/FlutterProjects
[mythcat@fedora ~]$ cd FlutterProjects/
[mythcat@fedora ~]$ wget https://storage.googleapis.com/flutter_infra_release/releases
/stable/linux/flutter_linux_3.3.10-stable.tar.xz
[mythcat@fedora ~]$ tar xf flutter_linux_3.3.10-stable.tar.xz
[mythcat@fedora ~]$
...

[mythcat@fedora FlutterProjects]$ ./flutter/bin/flutter doctor

┌─────────────────────────────────────────────────────────┐
│ A new version of Flutter is available!                  │
│                                                         │
│ To update to the latest version, run "flutter upgrade". │
└─────────────────────────────────────────────────────────┘
...

      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.

[✗] Chrome - develop for the web (Cannot find Chrome executable at
    google-chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.
[✓] Linux toolchain - develop for Linux desktop
[!] Android Studio (not installed)
[✓] VS Code (version 1.87.2)
[✓] Connected device (1 available)
[✓] HTTP Host Availability

! Doctor found issues in 3 categories.
[mythcat@fedora FlutterProjects]$ ./flutter/bin/flutter upgrade

...

    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.
[✓] Linux toolchain - develop for Linux desktop
[!] Android Studio (not installed)
[✓] VS Code (version 1.87.2)
[✓] Connected device (1 available)
[✓] Network resources

! Doctor found issues in 4 categories.

[mythcat@fedora FlutterProjects]$ ./flutter/bin/flutter config --enable-linux-desktop
Setting "enable-linux-desktop" value to "true".

You may need to restart any open editors for them to read new settings.

[mythcat@fedora FlutterProjects]$ mkdir examples
[mythcat@fedora FlutterProjects]$ cd examples/

[mythcat@fedora examples]$ ../flutter/bin/flutter create .
Creating project ....
Resolving dependencies... (5.1s)
Got dependencies.
Wrote 129 files.

All done!
You can find general documentation for Flutter at: https://docs.flutter.dev/
Detailed API documentation is available at: https://api.flutter.dev/
If you prefer video documentation, consider:
https://www.youtube.com/c/flutterdev

In order to run your application, type:

  $ cd .
  $ flutter run

Your application code is in ./lib/main.dart.

[mythcat@fedora examples]$ cd .
[mythcat@fedora examples]$ ls
analysis_options.yaml  ios    macos         README.md  windows
android                lib    pubspec.lock  test
examples.iml           linux  pubspec.yaml  web
[mythcat@fedora examples]$ ../flutter/bin/flutter run
The result is this simple default example: