diff -up firefox-52.0b8/js/src/jsmath.cpp.missing-getrandom firefox-52.0b8/js/src/jsmath.cpp

--- firefox-52.0b8/js/src/jsmath.cpp.missing-getrandom	2017-02-22 08:09:21.764353407 +0100

+++ firefox-52.0b8/js/src/jsmath.cpp	2017-02-22 08:10:36.939330775 +0100

@@ -78,7 +78,7 @@

 static_assert(GETRANDOM_NR == SYS_getrandom,

               "GETRANDOM_NR should match the actual SYS_getrandom value");

 #  endif

-# else

+# elif defined(GETRANDOM_NR)

 #  define SYS_getrandom GETRANDOM_NR

 # endif

@@ -721,7 +721,7 @@ js::GenerateRandomSeed()

     seed = (static_cast<uint64_t>(arc4random()) << 32) | arc4random();

 #elif defined(XP_UNIX)

     bool done = false;

-# if defined(__linux__)

+# if defined(__linux__) && defined(SYS_getrandom)

     // Try the relatively new getrandom syscall first. It's the preferred way

     // on Linux as /dev/urandom may not work inside chroots and is harder to

     // sandbox (see bug 995069).