## Summary When setting a virtual memory limit of <1.3GB, GHC wont start with the error: > ghc: failed to create OS thread: Cannot allocate memory This has led to broken Haskell support in Compiler Explorer ("godbolt"): https://github.com/compiler-explorer/compiler-explorer/issues/1412 This is probably due to #9706 "New block-structured heap organization for 64-bit" Other related issues: \ #14193 "Add RTS flag to disable 1TB address space allocation" \ #8604 "Some stack/vmem limits (ulimit) combinations causing GHC to fail" \ ## Steps to reproduce In a new terminal: `ulimit -v 1258292` Then try to run `ghc`. In a different, new, terminal, try 1.3GB: `ulimit -v 1363148` Then run `ghc` which should work. Or see failure in Compiler Explorer: https://gcc.godbolt.org/z/zKs4a6 ## Environment * GHC version used: 8.6.5, (8.8.3 through stack), Compiler Explorer uses 8.6.1 and 8.6.2 Optional: * Operating System: Ubuntu 20.04, Kernel 5.8.0-050800-generic * System Architecture: AMD64 (AMD Ryzen 7 4700U)