Changes in "include/nuttx" do not propagate to libc

[Javier Alonso <ja...@geotab.com.INVALID>]

Hello,

I've been playing a bit with NuttX, making changes to the ".version"
file so as to generate a custom "version.h". I was expecting libraries
from "libc" to include those changes, but to my surprise they are not
propagated - this is, re-compilation is not triggered.

In particular, the "lib_utsuname.c" is not even detecting the changes.
I've tried adding some random stuff to "include/nuttx" files that are
in use by "libc" but that doesn't trigger changes, either.

I'm looking for some guidance. My guess is that "libc" has some
special configurations I'm missing, as other drivers/files are
re-compiled whenever I change the version.h.

Best regards,

Javier Alonso

Re: Changes in "include/nuttx" do not propagate to libc

[Javier Alonso <ja...@geotab.com.INVALID>]

[Follow-up]

I have been taking a deeper look, and at some point the whole "libc"
**was not recompiling** on any header change - which looked and was a
Makefile error. The fix was simple: Remove the double "$(DELIM)" from
the dependencies, as it turns out the "Make.dep" file only has one
delimiter. This was introduced in an attempt to fix Windows
compilation problems, but caused incremental builds to stop working on
any other machine as "make" is looking for a file with double
delimiter on its name.

We were using an older version of NuttX, that's why we had this
problem. However, it has already been fixed on PR
https://github.com/apache/nuttx/pull/7572. We will pull the changes
and cherry-pick those.

PS: Full explanation with images is available at
https://github.com/apache/nuttx/pull/16564#issuecomment-2994364394.

Best regards,

Javier Alonso

Re: Changes in "include/nuttx" do not propagate to libc

[Javier Alonso <ja...@geotab.com.INVALID>]

Hello again,

I've created the following PR with a potential fix/workaround:
https://github.com/apache/nuttx/pull/16564

However, I'm not sure if this is the best way to go. Any hints are
really appreciated.

BR,

Javier Alonso

On Fri, Jun 20, 2025 at 1:30 PM Javier Alonso <ja...@geotab.com> wrote:
>
> Hello,
>
> I've been playing a bit with NuttX, making changes to the ".version"
> file so as to generate a custom "version.h". I was expecting libraries
> from "libc" to include those changes, but to my surprise they are not
> propagated - this is, re-compilation is not triggered.
>
> In particular, the "lib_utsuname.c" is not even detecting the changes.
> I've tried adding some random stuff to "include/nuttx" files that are
> in use by "libc" but that doesn't trigger changes, either.
>
> I'm looking for some guidance. My guess is that "libc" has some
> special configurations I'm missing, as other drivers/files are
> re-compiled whenever I change the version.h.
>
> Best regards,
>
> Javier Alonso