## Summary ghc 8.8.1 compiled on macOS 10.15 with system compiler (Xcode 11.1) completes bootstrap, but the compiler later fails to run simple programs with a memory-related error: ``` ghc: mmap 131072 bytes at 0x0: Operation not permitted ghc: Try specifying an address with +RTS -xm<addr> -RTS ghc: internal error: m32_allocator_init: Failed to map (GHC version 8.8.1 for x86_64_apple_darwin) ``` This is reproducible in several setups, both inside VMs and on physical hardware. ## Steps to reproduce On macOS 10.15 Catalina, with Xcode 11.1 (system compiler): - ghc 8.8.1 is built from ghc-8.8.1-src.tar.xz (as part of Homebrew) - bootstrap completes - Run a simple test, watch if fail: ``` rmeur /tmp $ cat hello.rs main = putStrLn "Hello Homebrew" rmeur /tmp $ /usr/local/Cellar/ghc/8.8.1/bin/runghc -v hello.rs Glasgow Haskell Compiler, Version 8.8.1, stage 2 booted by GHC version 8.6.5 Using binary package database: /usr/local/Cellar/ghc/8.8.1/lib/ghc-8.8.1/package.conf.d/package.cache package flags [] loading package database /usr/local/Cellar/ghc/8.8.1/lib/ghc-8.8.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.3 wired-in package integer-wired-in mapped to integer-gmp-1.0.2.0 wired-in package base mapped to base-4.13.0.0 wired-in package rts mapped to rts wired-in package template-haskell mapped to template-haskell-2.15.0.0 wired-in package ghc mapped to ghc-8.8.1 package flags [] loading package database /usr/local/Cellar/ghc/8.8.1/lib/ghc-8.8.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.3 wired-in package integer-wired-in mapped to integer-gmp-1.0.2.0 wired-in package base mapped to base-4.13.0.0 wired-in package rts mapped to rts-1.0 wired-in package template-haskell mapped to template-haskell-2.15.0.0 wired-in package ghc mapped to ghc-8.8.1 *** Desugar: *** Simplify [expr]: !!! Simplify [expr]: finished in 0.18 milliseconds, allocated 0.056 megabytes *** CorePrep [expr]: !!! CorePrep [expr]: finished in 3.17 milliseconds, allocated 1.705 megabytes *** ByteCodeGen [Ghci1]: !!! ByteCodeGen [Ghci1]: finished in 0.10 milliseconds, allocated 0.029 megabytes ghc: mmap 131072 bytes at 0x0: Operation not permitted ghc: Try specifying an address with +RTS -xm<addr> -RTS ghc: internal error: m32_allocator_init: Failed to map (GHC version 8.8.1 for x86_64_apple_darwin) Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug ``` ## Expected behavior The program should run without error. ## Environment * GHC version used: Optional: * Operating System: macOS 10.15 Catalina * System Architecture: x86_64