[vtk-developers] Moved Mirkwood ninja dashboards to nightly

[Brad King]

On 04/01/2013 02:46 PM, Brad King wrote:
> If someone encountering the problem can narrow down a dependency
> failure to an example test case then the problem can be reported,

Here is a minimal example reproducible on Linux::

 cmake_minimum_required(VERSION 2.8.10)
 project(DependSideEffect C)
 add_library(A a.c)
 add_custom_command(
   TARGET A POST_BUILD
   COMMAND cp ${CMAKE_CURRENT_SOURCE_DIR}/a.c a.txt
   )
 add_custom_command(
   OUTPUT b.txt
   DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/a.txt
   COMMAND cp a.txt b.txt
   )
 add_custom_target(B ALL DEPENDS b.txt)
 add_dependencies(B A)

Building with Ninja fails with::

 ninja: error: 'a.txt', needed by 'b.txt', missing and no known rule to make it

Relevant portions of build.ninja:

 build libA.a: C_STATIC_LIBRARY_LINKER CMakeFiles/A.dir/a.c.o
   POST_BUILD = cd ".../build" && cp .../a.c a.txt
 ...
 build b.txt: CUSTOM_COMMAND a.txt || libA.a
   COMMAND = cd ".../build" && cp a.txt b.txt
 ...

The rule for "b.txt" has an order-only dependency on "libA.a" and
a full dependency on "a.txt".  Ninja does not wait for the order-only
dependencies to be up to date before evaluating the full dependencies
and then complains that the latter is missing.

-Brad