[PATCH 3/6] daemon: On aarch64, use increments of 16 on the stack.

[Efraim Flashner]

man2 clone: EINVAL: ... on aarch64, child_stack must be a multiple of 16.

* nix/libstore/build.cc (DerivationGoal::startBuilder): When on aarch64,
when calling clone(), increment the stack by 16.
---
 nix/libstore/build.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index cebc404d1..362b2d91d 100644
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -2008,7 +2008,12 @@ void DerivationGoal::startBuilder()
        char stack[32 * 1024];
        int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | 
SIGCHLD;
        if (!fixedOutput) flags |= CLONE_NEWNET;
-       pid = clone(childEntry, stack + sizeof(stack) - 8, flags, this);
+// if statements are hard, fix this
+//#if __AARCH64__
+       pid = clone(childEntry, stack + sizeof(stack) - 16, flags, this);
+//#else
+//     pid = clone(childEntry, stack + sizeof(stack) - 8, flags, this);
+//#endif
        if (pid == -1)
            throw SysError("cloning builder process");
     } else
-- 
2.11.1