Overview

There are so many Linux distributions out there, each using different package managers, init systems, and more. Some packages are built for specific distributions, with the most popular formats being .rpm and .deb. Unfortunately, you might only find support for the one your system doesn’t use. You could face a situation where your package manager is different, but the software you want to install is only available in another format. In such cases, your best options are usually snap or flatpak. In the worst-case scenario, you’ll need to resort to building from source, using containers, or converting the package yourself. Unfortunately, this guide is for the worst case scenario where you have no support for other package and you end up deciding to convert it yourself. (and maybe you can publish them in copr or other third party package repositories, so that others don’t end up doing the hard way like you did)

Getting Started!

We are going to be using Fedora Linux here (which is an RPM-based distro), and make sure you have the certain tools installed.

rpmdevtools: A package providing various utilities for RPM packaging. It includes scripts, create .spec files, and more.
rpmbuild: A text file that defines how the package is built, installed and configured.
tar: Used to create archives of your source code, usually needed for the SOURCES/ directory. (iirc, tar will be installed by default)
ar: A tool used to create and extract archives. Which we definitely need to extract the Debian packages.
make, gcc: Helps you build the binaries before packaging them.

Install:

sudo dnf install rpm-build rpmdevtools make gcc

Setup RPM Build Environment

rpmdev-setuptree

It creates the environment in your home directory:

# directory structure
~/rpmbuild/
├── BUILD
├── RPMS
├── SOURCES
├── SPECS
├── SRPMS

BUILD/: A chroot environment where the actual package will be built here and the data will be deleted once its completed.
RPMS/: This is where the .rpm package will be built and stored.
SOURCES/: For storing the source code in a .tar archive.
SPECS/: Storing .specs file for each packaging works.
SRPMS/: This is where the .src.rpm package wil be build and stored(Source RPM).

Converting Debian Package

I’m going to use hayase an application for streaming anime via torrents, as an example for converting it from .deb to .rpm package.

Note: This might not be 100% total conversion, but it will give you a package right away to start using it without any problem at. Although you might not be able to use all the features.

Extract The Debian Package

Download the package

# make sure to download the application you want and don't follow along the code by just copy pasting the commands...XD
wget https://github.com/hayase-app/ui/releases/download/v6.4.23/linux-hayase-6.4.23-linux.deb

Extract them inside SOURCES/ (its easier to convert them inside this directory rather than making it somewhere else)

mkdir hayase-6.4.23

mv linux-hayase-6.4.23-linux.deb hayase-6.4.23/

cd hayase-6.4.23
ar x linux-hayase-6.4.23-linux.deb

Note: ar tool is used to extract the Debian package.

iamyaash@fedora:~/rpmbuild/SOURCES/linux-hayase-6.4.23-linux$ ll
total 67M
-rw-r--r--. 1 iamyaash iamyaash 3.3K Aug 15 15:59 control.tar.gz
-rw-r--r--. 1 iamyaash iamyaash  67M Aug 15 15:59 data.tar.xz
-rw-r--r--. 1 iamyaash iamyaash    4 Aug 15 15:59 debian-binary

control.tar.gz: Contains the scriptlets (postrm, prerm, postinst, preinst), md5sums, control and more.
data.tar.xz: Contains the actual source code that runs the software.
debian-binary: Contains just the text of the packaging format version.

Archive The Final Build

After extracting the “Debian Package”, it will have data.tar.xz, control.tar.gz & debian-binary.

As the file names suggest, data.tar.xz contains the final build of the software. In simple terms, data.tar.xz is the software that is archived.

Let’s extract the data, move them inside a directory and archive it in gz format. Because, we need them to be archived in order to package it.

Extract data.tar.xz:

tar -xvJf data.tar.xz

iamyaash@fedora:~/rpmbuild/SOURCES/linux-hayase-6.4.23-linux$ ll
total 144M
-rw-r--r--. 1 iamyaash iamyaash 3.3K Aug 15 15:59 control.tar.gz
-rw-r--r--. 1 iamyaash iamyaash  67M Aug 15 15:59 data.tar.xz
-rw-r--r--. 1 iamyaash iamyaash    4 Aug 15 15:59 debian-binary
drwxr-xr-x. 1 iamyaash iamyaash   12 Aug 15 02:34 opt/
drwxr-xr-x. 1 iamyaash iamyaash   10 Aug 15 02:34 usr/

The data.tar.xz contains the final build of the software and we need to place them under a directory and archive it.

Move the build files into a directory named <name><version>/:

mkdir hayase-6.4.23/
mv opt/ usr/ hayase-6.4.23/

This would be directory structure after moving opt/ usr/ inside hayase-6.4.23/,

iamyaash@fedora:~/rpmbuild/SOURCES/linux-hayase-6.4.23-linux$ ll hayase-6.4.23/
total 4.0K
drwxr-xr-x. 1 iamyaash iamyaash   12 Aug 15 02:34 opt/
drwxr-xr-x. 1 iamyaash iamyaash   10 Aug 15 02:34 usr/

Archive the whole directory into tar.gz format.

tar -cvzf hayase-6.4.23.tar.gz hayase-6.4.23

Move the archive into the parent direcory SOURCES/:

iamyaash@fedora:~/rpmbuild/SOURCES$ ll
total 95M
drwxr-xr-x. 1 iamyaash iamyaash   52 Aug 15 16:04 hayase-6.4.16/
-rw-r--r--. 1 iamyaash iamyaash  95M Aug 15 16:05 hayase-6.4.23.tar.gz

RPM Packaging

Finally, we archived the source code, placed it under SOURCES/ and we have completed preparing the source code part. Now, its time to focus on writing installation instruction in a .spec file.

Installation Instructions

Create a .spec file under SPECS/ directory:

touch ~/rpmbuild/SPECS/hayase.spec
# name it however you want, but keep it concise

Modify the .spec file according to the software you want to package. Keep in mind that installation steps may differ depending on the project and the technologies it uses. Make sure to write accurate instructions instead of directly copying the examples provided here.
The good news is that we don’t need to start everything from scratch. We already have a template .spec file as a base, and we can build on top of the existing structure.

Sample .spec file:

Name:           hello
Version:        1.0
Release:        1%{?dist}
Summary:        Simple Hello World program
License:        MIT
URL:            http://example.com/
Source0:        hello-1.0.tar.gz

BuildRequires:  gcc

%description
A simple Hello World program packaged as an RPM example.

%prep
%setup -q

%build
gcc %{optflags} -o hello hello.c

%install
mkdir -p %{buildroot}/usr/bin
install -m 0755 hello %{buildroot}/usr/bin/hello

%files
/usr/bin/hello

%changelog
* Tue Jul 01 2025 Yashwanth Rathakrishnan <you@example.com> - 1.0-1
- Initial package

Extract Instruction Files In Debian Package

The essential installation instructions are already available in the Debian package. Our task is simply to adapt and convert those instructions into the RPM packaging format, following its standards.

Extract control.tar.gz

tar -xvzf control.tar.gz

It contains the scriptlets, control file, and the signature.

$ tar --exclude="/*" -tzf control.tar.gz 
./
./postrm
./control
./postinst
./md5sums

Note: These files are essential to write the build instructions. We are just going to copy them and convert those to RPM standards.

Tip: Open a browser, search the equivalent of the listed files you have and place them accordingly in the .spec file.

Write Instructions In Spec File (Convertion)

Use cat, then copy the contents, convert them to RPM standard if necessary and paste them in .spec file under the respective macros.

postrm in Debian == postun in RPM

%postun
#!/bin/bash

# Delete the link to the binary
if command -v update-alternatives >/dev/null 2>&1; then
    update-alternatives --remove hayase %{_bindir}/hayase || true
else
    rm -f %{_bindir}/hayase
fi

postinst in Debian == post in RPM

%post
#!/bin/bash

if type update-alternatives 2>/dev/null >&1; then
    # Remove previous link if it doesn't use update-alternatives
    if [ -L '/usr/bin/hayase' -a -e '/usr/bin/hayase' -a "`readlink '/usr/bin/hayase'`" != '/etc/alternatives/hayase' ]; then
        rm -f '/usr/bin/hayase'
    fi
    update-alternatives --install '/usr/bin/hayase' 'hayase' '/opt/Hayase/hayase' 100 || ln -sf '/opt/Hayase/hayase' '/usr/bin/hayase'
else
    ln -sf '/opt/Hayase/hayase' '/usr/bin/hayase'
fi

# Check if user namespaces are supported by the kernel and working with a quick test:
if ! { [[ -L /proc/self/ns/user ]] && unshare --user true; }; then
    # Use SUID chrome-sandbox only on systems without user namespaces:
    chmod 4755 '/opt/Hayase/chrome-sandbox' || true
else
    chmod 0755 '/opt/Hayase/chrome-sandbox' || true
fi

if hash update-mime-database 2>/dev/null; then
    update-mime-database /usr/share/mime || true
fi

if hash update-desktop-database 2>/dev/null; then
    update-desktop-database /usr/share/applications || true
fi

control in Debian => First few lines with different naming convention in .spec file

Package: hayase
Version: 6.4.23
License: unknown
Vendor: ThaUnknown
Architecture: amd64
Maintainer: ThaUnknown
Installed-Size: 238840
Depends: libgtk-3-0, libnotify4, libnss3, libxss1, libxtst6, xdg-utils, libatspi2.0-0, libuuid1, libsecret-1-0
Recommends: libappindicator3-1
Section: default
Priority: optional
Homepage: https://hayase.app
Description: 
  Hayase - Torrent streaming made simple

Name:		hayase
Version:	6.4.23
Release:    1%{?dist}
Summary:	Hayase - Torrent streaming made simple
License:	BSL-1.1
URL:		https://hayase.app
Source0:	hayase-6.4.23.tar.gz
Packager:   Yashwanth Rathakrishnan <yaasharc@gmail.com>
Vendor:     ThaUnknown
Requires:   gtk3, libnotify, nss, libXScrnSaver, libXtst, xdg-utils, at-spi2-core, libuuid, libsecret
Suggests: 	libappindicator-gtk3
BuildArch:  x86_64
%description
Hayase - Torrent streaming made simple

Here, you can notice the differences in naming conventions such as
- Name == Package,
- %description == Description,
- URL == Homepage,
- BuildArch == Architecture and more.
You don’t need to worry about the md5sums; they are just signatures generated by the packager. You can ignore them since you are only trying to package the software minimally.

Write Instruction for Installation (RPM Standards)

RPM .spec snippets needs sections, that fulfills the instructions.

%prep
%setup #verbose output
# %setup -q

%prep section:
- %setup extracts the source archive with verbose output.
- %setup -q for quiet extraction.

%install
rm -rf %{buildroot}
mkdir -p %{buildroot}
cp -a opt %{buildroot}/opt
cp -a usr %{buildroot}/usr
ls -lR %{buildroot}

%install section:
- Removes any existing buildroot directory.
- Creates the buildroot directory
- Copies opt/ & usr/ (arhived previously) directories from the build sources into the buildroot.
- List recursively the contents of the buildroot for verification.

RPM follows a different packaging style, so it builds the package under BUILD/ directory and that’s why we are writing instructions like this. I know it will take some time to understand, but it’s just that it copies the sources somewhere and package it effectively rather than packaing in already existing directory that might cause conflicts later possibly because of other files existing in the directory.

%check section:
- Empty here, typically used for running tests. You can leave it empty if no tests are specified

%files
/opt/Hayase/*
/usr/share/applications/hayase.desktop
/usr/share/icons/hicolor/16x16/apps/hayase.png
/usr/share/icons/hicolor/32x32/apps/hayase.png
/usr/share/icons/hicolor/48x48/apps/hayase.png
/usr/share/icons/hicolor/64x64/apps/hayase.png
/usr/share/icons/hicolor/128x128/apps/hayase.png
/usr/share/icons/hicolor/256x256/apps/hayase.png
/usr/share/icons/hicolor/512x512/apps/hayase.png
%doc /usr/share/doc/hayase/changelog.gz
%license LICENSE

%files section:
- Lists documentation and license files that will be included in the package.
- %doc - indicates the documentation for the package.
- %license - LICENSE of the package.

My Version of Spec File

Name:		hayase
Version:	6.4.15
Release:    1%{?dist}
Summary:	Hayase - Torrent streaming made simple
License:	BSL-1.1
URL:		https://hayase.app
Source0:	hayase-6.4.15.tar.gz
Packager:   Yashwanth Rathakrishnan <yaasharc@gmail.com>
Vendor:     ThaUnknown
Requires:   gtk3, libnotify, nss, libXScrnSaver, libXtst, xdg-utils, at-spi2-core, libuuid, libsecret
Suggests: 	libappindicator-gtk3
BuildArch:  x86_64

%global debug_package %{nil}

%description
Hayase - Torrent streaming made simple

%prep
%setup #verbose output
# %setup -q

%install
rm -rf %{buildroot}
mkdir -p %{buildroot}
cp -a opt %{buildroot}/opt
cp -a usr %{buildroot}/usr
ls -lR %{buildroot}

%check

%files
/opt/Hayase/*
/usr/share/applications/hayase.desktop
/usr/share/icons/hicolor/16x16/apps/hayase.png
/usr/share/icons/hicolor/32x32/apps/hayase.png
/usr/share/icons/hicolor/48x48/apps/hayase.png
/usr/share/icons/hicolor/64x64/apps/hayase.png
/usr/share/icons/hicolor/128x128/apps/hayase.png
/usr/share/icons/hicolor/256x256/apps/hayase.png
/usr/share/icons/hicolor/512x512/apps/hayase.png
%doc /usr/share/doc/hayase/changelog.gz
%license LICENSE

%post
#!/bin/bash

if type update-alternatives 2>/dev/null >&1; then
    # Remove previous link if it doesn't use update-alternatives
    if [ -L '/usr/bin/hayase' -a -e '/usr/bin/hayase' -a "`readlink '/usr/bin/hayase'`" != '/etc/alternatives/hayase' ]; then
        rm -f '/usr/bin/hayase'
    fi
    update-alternatives --install '/usr/bin/hayase' 'hayase' '/opt/Hayase/hayase' 100 || ln -sf '/opt/Hayase/hayase' '/usr/bin/hayase'
else
    ln -sf '/opt/Hayase/hayase' '/usr/bin/hayase'
fi

# Check if user namespaces are supported by the kernel and working with a quick test:
if ! { [[ -L /proc/self/ns/user ]] && unshare --user true; }; then
    # Use SUID chrome-sandbox only on systems without user namespaces:
    chmod 4755 '/opt/Hayase/chrome-sandbox' || true
else
    chmod 0755 '/opt/Hayase/chrome-sandbox' || true
fi

if hash update-mime-database 2>/dev/null; then
    update-mime-database /usr/share/mime || true
fi

if hash update-desktop-database 2>/dev/null; then
    update-desktop-database /usr/share/applications || true
fi


%postun
#!/bin/bash

# Delete the link to the binary
if command -v update-alternatives >/dev/null 2>&1; then
    update-alternatives --remove hayase %{_bindir}/hayase || true
else
    rm -f %{_bindir}/hayase
fi

%changelog
* Sun Jul 20 2025 Yashwanth Rathakrishnan <yaasharc@gmail.com> 6.4.15-1
- packaged upstream version 6.4.15 converted from DEB for Copr
- fixed scriptlet failed, exit status 2, by adding /sbin/update-alternatives

Summary

I wanted to share this post, mainly because it helped me learn more about packaging and some of the fundamental knowledge about why they are being packaged like that. I mean there are some tools like alien which helps you convert Debian pacakge to .rpm but I just wanted to do it the manual way and learn how it’s done behind the scene. I think it makes sense right? If you can handle the manual way, you can definitely handle the automatic way. By now, you would have a basic idea on how to convert packages, and some basic understand as well.

Thanks for reading!!

Overview#

Getting Started!#

Setup RPM Build Environment#

Converting Debian Package#

Extract The Debian Package#

Archive The Final Build#

RPM Packaging#

Installation Instructions#

Extract Instruction Files In Debian Package#

Write Instructions In Spec File (Convertion)#

Write Instruction for Installation (RPM Standards)#

My Version of Spec File#

Summary#