Is the "skip boot cycle" trick still needed?

[Jonathan Gibbons]

Using SKIP_BOOT_CYCLE=false has often flushed out bugs, and I would be 
concerned about its removal.

Is it really that hard to provide the same functionality in the new 
build system?  Surely, it should just be a matter of a couple of 
recursive makes at the top-level, the first into an "interim" build dir 
and the second using the result of the first as its ALT_BOOTDIR.

-- Jon


On 09/10/2012 04:43 AM, Magnus Ihse Bursie wrote:
> In the old system, one can set the oddly named SKIP_BOOT_CYCLE to 
> false (which, internally, sets the slightly more clearly named 
> DO_BOOT_CYCLE=true). This causes the product to build twice, the 
> second time using the first build result as the boot jdk.
>
> This has been used, as I understand it, as a "poor mans integration 
> test" -- if the build output could perform the feat of compiling the 
> JDK, then it can't be that broken.
>
> This kind of behaviour is not implemented in the new build system, and 
> I propose that it should not be. The cost for implementing this is 
> that all build system for all builds will be more complicated, but the 
> gains are more unclear. To me, this is just a test, and it's a bit odd 
> to have that as part of the build system. I also believe are now far 
> better tests using jtreg, and if they are lacking -- then the tests 
> should be improved, not the build system changed.
>
> Is there anyone who would be protesting if the SKIP_BOOT_CYCLE 
> functionality would be dropped in the new build system?
>
> /Magnus