| Message ID | 1413836616-4209-1-git-send-email-yann.morin.1998@free.fr |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Oct 20, 2014 at 10:23 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote: > When saving (aka updating) the configuration file of a kconfig package, > a subsequent call to "make" would rebuild the package, even though the > configuration did not actually change. > > It took quite a while to understand why. But the reason is so simple and > obvious, when you think about it: > > - $(@D)/.config depends on the config file $(BUSYBOX_CONFIG_FILE) > - busybox-update-config then copies $(@D)/.config back to the config > file $(BUSYBOX_CONFIG_FILE) > - so the config file is newer than $(@D)/.config > > So, in the next run, pkg-kconfig believes that it has to rebuild > busybox. Bummer... :-/ > > So, the fix is very trivial, and just requires asking "cp" to preserve > timestamps, so the dependency does not kick in at the next run. > > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> > Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com> Reviewed-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Dear Yann E. MORIN, On Mon, 20 Oct 2014 22:23:36 +0200, Yann E. MORIN wrote: > When saving (aka updating) the configuration file of a kconfig package, > a subsequent call to "make" would rebuild the package, even though the > configuration did not actually change. > > It took quite a while to understand why. But the reason is so simple and > obvious, when you think about it: > > - $(@D)/.config depends on the config file $(BUSYBOX_CONFIG_FILE) > - busybox-update-config then copies $(@D)/.config back to the config > file $(BUSYBOX_CONFIG_FILE) > - so the config file is newer than $(@D)/.config > > So, in the next run, pkg-kconfig believes that it has to rebuild > busybox. Bummer... :-/ > > So, the fix is very trivial, and just requires asking "cp" to preserve > timestamps, so the dependency does not kick in at the next run. > > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> > Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com> Applied, thanks. Thomas
diff --git a/package/pkg-kconfig.mk b/package/pkg-kconfig.mk index 071153a..ec58d69 100644 --- a/package/pkg-kconfig.mk +++ b/package/pkg-kconfig.mk @@ -66,7 +66,7 @@ $$(addprefix $(1)-,$$($(2)_KCONFIG_EDITORS)): $$($(2)_DIR)/.stamp_kconfig_fixup_ # Target to copy back the configuration to the source configuration file $(1)-update-config: $$($(2)_DIR)/.stamp_kconfig_fixup_done - cp -f $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE) + cp --preserve=timestamps -f $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE) endef # inner-kconfig-package
When saving (aka updating) the configuration file of a kconfig package, a subsequent call to "make" would rebuild the package, even though the configuration did not actually change. It took quite a while to understand why. But the reason is so simple and obvious, when you think about it: - $(@D)/.config depends on the config file $(BUSYBOX_CONFIG_FILE) - busybox-update-config then copies $(@D)/.config back to the config file $(BUSYBOX_CONFIG_FILE) - so the config file is newer than $(@D)/.config So, in the next run, pkg-kconfig believes that it has to rebuild busybox. Bummer... :-/ So, the fix is very trivial, and just requires asking "cp" to preserve timestamps, so the dependency does not kick in at the next run. Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com> --- package/pkg-kconfig.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)