Missing legacy vcl header file in otbMosiacFunctors

Description

Hi OTB Team!

There was a non-deterministic build issue reported in Nix packages (thanks to qbisicwate), where it was observed that the build seems to fail on certain filesystem such as btrfs but not on ext4. The issue has been explained more in detail here, adding the directly the vcl_legacy_aliases.h in otbMosaicFunctors.h seems to fix the issue.

Related disucssion:

• Ref1
• Ref2

Would it be possible to add this changes or do you recommend any other possible solution ?

Thanks!

Steps to reproduce

Build succeeds:

dd if=/dev/zero of=block.img bs=10M count=1000
mkfs.ext4 block.img
sudo mount -o loop block.img /tmp
nix build github:NixOS/nixpkgs/nixos-25.05#otb --rebuild

Build Fails:

dd if=/dev/zero of=block.img bs=10M count=1000
mkfs.btrfs block.img
sudo mount -o loop block.img /tmp
nix build github:NixOS/nixpkgs/nixos-25.05#otb --rebuild

Configuration information

OTB Nixpkgs