[Pkg-javascript-devel] Bug#785696: libv8: newer upstream version that works on arm64

[Edmund Grimley Evans]

Source: libv8-3.14
Version: 3.14.5.8-8.1
Severity: wishlist

Hi,

The version of libv8 currently in Debian unstable is very old. It
would be nice to have a newer version that works on arm64 so all the
dependencies could be built and tested.

Obviously you don't want lots of different versions of libv8 in
Debian. I looked into the matter a little and am putting what I
discovered below in case anyone finds it useful.

V8's repo is here:

https://chromium.googlesource.com/v8/v8

You can see from the ChangeLog that there is a new version X.Y, with
useful but incompatible changes, roughly every 6 weeks. It's currently
on 4.5.2. Debian's current package is apparently based on "2012-10-22:
Version 3.14.5". The first mention of "ARM64" in the ChangeLog is at
"2014-03-24: Version 3.25.23".

The main user of libv8 in Debian is nodejs, and that presumably
explains why Jessie has libv8-3.14 rather than any other version.

Node.js's repo is here:

https://github.com/joyent/node

Node.js includes its own copy of V8 in deps/v8/. Node.js's ChangeLog
gives an idea of which versions of V8 correspond to which versions of
Node.js.

The Debian packages built from nodejs depend on the packages built
from libv8-3.14: Debian does not include a separate version of V8 for
use by Node.js, though there is, I think, a separate version of V8
bundled with Chrome.

Debian's nodejs is currently based on 0.10.38, the latest, and perhaps
last, 0.10 release. According to the ChangeLog, Node.js 0.10 was
always based on V8 3.14: 0.10.0 is dated 2013.03.11, and 0.10.38 is
dated 2015.03.23. So Node.js was using V8 3.14.5 29 months after
upstream had finished with it. You can see in Node.js's ChangeLog how
various fixes had to be backported.

Node.js uses the odd-even convention, so 0.11 is unstable.

Node.js's 0.12.0 is dated 2015.02.06, and the latest is 0.12.3, dated
2015.05.13. These are all based on V8 3.28.x. Moreover, I read here
(https://github.com/joyent/node/issues/9162) that "V8 won't be
upgraded past 3.28 for v0.12 because it requires a C++11 capable
compiler".

So I would guess that if Debian wants to continue having nodejs based
on a separate libv8 package then the thing to do is add a libv8-3.28
package and then upgrade nodejs to 0.12.something.