here is my attempt to add an overlay to the nix ros overlay so i can ad a required compiler flag. I’m using this example to try and learn how overlays work in a flake context.
I am very new to Nix as well.
The goal of this attempt is to produce a derivation (am i using that word right?) that is just like the rplidar-ros package in the nix ros overlay, except it has the cmakeFlags changed.
inputs = {
nix-ros-overlay.url = "github:lopsided98/nix-ros-overlay";
nixpkgs.follows = "nix-ros-overlay/nixpkgs"; # IMPORTANT!!!
};
outputs = { self, nix-ros-overlay, nixpkgs }:
nix-ros-overlay.inputs.flake-utils.lib.eachDefaultSystem (system:
let
pkgs = import nixpkgs {
inherit system;
overlays = [
nix-ros-overlay.overlays.default
(final: prev: {
rosPackages = prev.rosPackages // {
humble = prev.rosPackages.humble // {
depthai-ros = prev.rosPackages.humble.depthai-ros.overrideAttrs (oldAttrs: {
cmakeFlags = (oldAttrs.cmakeFlags or []) ++ [ "-DDEPTHAI_ENABLE_BACKWARD=OFF_____THIS_DOES_NOT_HAPPEN________________" ];
});
};
};
})
];
};
in {
devShells.default = pkgs.mkShell {
name = "Example project";
packages = with pkgs.rosPackages.humble; [
pkgs.colcon
ros-core
nav2-core
rplidar-ros
depthai-ros
];
};
});
nixConfig = {
extra-substituters = [ "https://ros.cachix.org" ];
extra-trusted-public-keys = [ "ros.cachix.org-1:dSyZxI8geDCJrwgvCOHDoAfOm5sV1wCPjBkKL+38Rvo=" ];
};
}
What happens is the overlay attempt has no effect at all.
To ensure changes to depthai-ros propagate to its dependents, you must use overrideScope. You can find more documentation here.
I reworked the flakes file to use overrideScope, by basing it on this example
It now looks like this: (including an edit to this post to correct the name as mentioned below)
{
description = "Hero Jr.";
inputs = {
nixpkgs.url = "github:NixOS/nixpkgs?ref=master";
flake-utils.follows = "ros-flake/flake-utils";
ros-flake.url = "github:lopsided98/nix-ros-overlay";
};
outputs = { self, nixpkgs, ros-flake, flake-utils }:
flake-utils.lib.eachDefaultSystem
(system:
let
ros = ros-flake.legacyPackages.${system};
pkgs = import nixpkgs { inherit system; overlays = [ ]; };
humble-overrided = ros.humble.overrideScope (final: prev: {
depthai-ros = prev.depthai-ros.overrideAttrs (old: {
cmakeFlags = (old.cmakeFlags or []) ++ [ "-DDEPTHAI_ENABLE_BACKWARD=OFF_____THIS_DOES_NOT_HAPPEN________________" ];
});
});
in
{
inherit pkgs;
packages = {};
devShells.default =
pkgs.mkShell {
buildInputs = (with humble-overrided; [
#pkgs.colcon
ros-core
nav2-core
rplidar-ros
depthai-ros
]);
};});
nixConfig = {
extra-substituters = [ "https://ros.cachix.org" "https://robossembler.cachix.org" ];
extra-trusted-public-keys = [
"ros.cachix.org-1:dSyZxI8geDCJrwgvCOHDoAfOm5sV1wCPjBkKL+38Rvo="
"robossembler.cachix.org-1:56jBJHroRQSGpZFkW8XMquuzQTjAF/XTo6MogmBM7SQ="
];
};
}
and still find that the override has no effect,
ros-humble-depthai> cmake flags: -DCMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY=OFF -DCMAKE_FIND_USE_PACKAGE_REGISTRY=OFF -DCMAKE_EXPORT_NO_PACKAGE_REGISTRY=ON -DCMAKE_BUILD_TYPE=Release -DBUIL
D_TESTING=OFF -DCMAKE_INSTALL_LOCALEDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/share/locale -DCMAKE_INSTALL_LIBEXECDIR=/nix/store/kqncqlsgld3l8z72wwrs7c6
31qhzz1l9-ros-humble-depthai-2.24.0-r1/libexec -DCMAKE_INSTALL_LIBDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/lib -DCMAKE_INSTALL_DOCDIR=/nix/store/kqncql
sgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/share/doc/depthai -DCMAKE_INSTALL_INFODIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/share/info -DCMA
KE_INSTALL_MANDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/share/man -DCMAKE_INSTALL_OLDINCLUDEDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-d
epthai-2.24.0-r1/include -DCMAKE_INSTALL_INCLUDEDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/include -DCMAKE_INSTALL_SBINDIR=/nix/store/kqncqlsgld3l8z72wwr
s7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/sbin -DCMAKE_INSTALL_BINDIR=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/bin -DCMAKE_INSTALL_NAME_DIR=/nix/store/kqn
cqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1/lib -DCMAKE_POLICY_DEFAULT_CMP0025=NEW -DCMAKE_OSX_SYSROOT= -DCMAKE_FIND_FRAMEWORK=LAST -DCMAKE_STRIP=/nix/store/lb6y9a5cf9fqvkp
67y5cdzpy909zryhf-gcc-wrapper-13.2.0/bin/strip -DCMAKE_RANLIB=/nix/store/lb6y9a5cf9fqvkp67y5cdzpy909zryhf-gcc-wrapper-13.2.0/bin/ranlib -DCMAKE_AR=/nix/store/lb6y9a5cf9fqvkp67y5cdzpy909zr
yhf-gcc-wrapper-13.2.0/bin/ar -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_INSTALL_PREFIX=/nix/store/kqncqlsgld3l8z72wwrs7c631qhzz1l9-ros-humble-depthai-2.24.0-r1 -DAMENT_CMAK
E_ENVIRONMENT_PARENT_PREFIX_PATH_GENERATION:BOOL=OFF -DPython3_EXECUTABLE:FILEPATH=/nix/store/dz8lm4h0ivibad5kfc0ya3p3zqyd2fyf-python3-3.11.7/bin/python3.11 -DAMENT_CMAKE_ENVIRONMENT_PARE
NT_PREFIX_PATH_GENERATION:BOOL=OFF -DPython3_EXECUTABLE:FILEPATH=/nix/store/dz8lm4h0ivibad5kfc0ya3p3zqyd2fyf-python3-3.11.7/bin/python3.11
is there anything else i might do to try and understand how to use overlays to set cmake flags?
Are you trying to override depthai-ros or rplidar-ros?
Thanks for taking a look at this!
I’m trying to override depthai
oops, sorry i swapped them in switching to the new approach
the override looks like ths:
humble-overrided = ros.humble.overrideScope (final: prev: {
depthai-ros = prev.depthai-ros.overrideAttrs (old: {
cmakeFlags = (old.cmakeFlags or []) ++ [ "-DDEPTHAI_ENABLE_BACKWARD=OFF_____THIS_DOES_NOT_HAPPEN________________" ];
});
});
in
and still has no effect
To really answer your question, I mostly want to learn how to use overrides so i can make more of the packages in nix-ros-overlay work. Needing cmake changes has been very common in my use of it so far.
Maybe try adding an apostrophe to overrideScope? (i.e. overrideScope') No clue what the difference is, still investigating, but the wiki uses the one with an apostrophe so maybe it’s worth a shot.
that gives:
error: attribute 'overrideScope'' missing
Maybe try
humble-overrided = ros.humble.overrideScope (final: prev: {
depthai-ros = prev.depthai-ros.overrideAttrs (old: rec {
cmakeFlags = (old.cmakeFlags or []) ++ [ "-DDEPTHAI_ENABLE_BACKWARD=OFF_____THIS_DOES_NOT_HAPPEN________________" ];
preConfigure = (old.preConfigure or "") + ''
export CMAKE_ARGS=$cmakeFlags "''${cmakeFlagsArray[@]}"
'';
});
});
in
note the usage of the rec keyword in prev.depthai-ros.overrideAttrs (old: rec {