The transitional package libpango1.0-0 has been removed from Debian Bullseye. The package dependency needs to be changed to libpango-1.0-0 or libpango-1.0-0 | libpango1.0-0.
~$ sudo apt dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
gconf-service gconf2 gconf2-common libappindicator1 libdbusmenu-gtk4 libgconf-2-4 libindicator7 libpangox-1.0-0
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
balena-etcher-electron libpango1.0-0
The following packages will be upgraded:
gir1.2-pango-1.0 libpango-1.0-0 libpango-1.0-0:i386 libpangocairo-1.0-0 libpangocairo-1.0-0:i386 libpangoft2-1.0-0 libpangoft2-1.0-0:i386 libpangoxft-1.0-0
8 upgraded, 0 newly installed, 2 to remove and 0 not upgraded.
Need to get 683 kB of archives.
After this operation, 283 MB disk space will be freed.
Please fix the dependencies. Thank you!
Had a quick browse, and the reference to libpango seems to be here.

Etcher version:
1.5.82
Operating system and architecture:
Debian Bullseye amd64
I just fixed it but had to rebuild the deb package.
Download the .deb installer file
Inside the folder your downloaded the file run dpkg-deb -R ./balena-etcher-electron_1.5.80_amd64.deb balena-etcher-electron
Edit file balena-etcher-electron/DEBIAN/control and replace libpango1.0-0 with libpango-1.0-0
Rebuild .deb installer running dpkg-deb -b balena-etcher-electron balena-etcher-electron_1.5.80-fixed_amd64.deb
Install balena-etcher-electron using the fixed installer running sudo dpkg balena-etcher-electron_1.5.80-fixed_amd64.deb
sudo dpkg -i balena-etcher-electron_1.5.80-fixed_amd64.deb
Seleccionando el paquete balena-etcher-electron previamente no seleccionado.
(Leyendo la base de datos ... 508614 ficheros o directorios instalados actualmente.)
Preparando para desempaquetar balena-etcher-electron_1.5.80-fixed_amd64.deb ...
Desempaquetando balena-etcher-electron (1.5.80) ...
Configurando balena-etcher-electron (1.5.80) ...
Procesando disparadores para desktop-file-utils (0.24-1) ...
Procesando disparadores para mime-support (3.64) ...
Procesando disparadores para hicolor-icon-theme (0.17-2) ...


Final steps
cd /opt/balenaEtcher
sudo chown root:$USER chrome-sandbox
sudo chmod 4755 chrome-sandbox



cd /opt/balenaEtcher
sudo chown root:$USER chrome-sandbox
sudo chmod 4755 chrome-sandbox
Is that the fix for #3129 ? :shrug:
fixed in v1.5.84
Most helpful comment
I just fixed it but had to rebuild the deb package.
Download the .deb installer file
Inside the folder your downloaded the file run dpkg-deb -R ./balena-etcher-electron_1.5.80_amd64.deb balena-etcher-electron
Edit file balena-etcher-electron/DEBIAN/control and replace libpango1.0-0 with libpango-1.0-0
Rebuild .deb installer running dpkg-deb -b balena-etcher-electron balena-etcher-electron_1.5.80-fixed_amd64.deb
Install balena-etcher-electron using the fixed installer running sudo dpkg balena-etcher-electron_1.5.80-fixed_amd64.deb
sudo dpkg -i balena-etcher-electron_1.5.80-fixed_amd64.deb Seleccionando el paquete balena-etcher-electron previamente no seleccionado. (Leyendo la base de datos ... 508614 ficheros o directorios instalados actualmente.) Preparando para desempaquetar balena-etcher-electron_1.5.80-fixed_amd64.deb ... Desempaquetando balena-etcher-electron (1.5.80) ... Configurando balena-etcher-electron (1.5.80) ... Procesando disparadores para desktop-file-utils (0.24-1) ... Procesando disparadores para mime-support (3.64) ... Procesando disparadores para hicolor-icon-theme (0.17-2) ...Final steps
cd /opt/balenaEtchersudo chown root:$USER chrome-sandboxsudo chmod 4755 chrome-sandbox