I tried building Swift's master branch on Ubuntu 20.04, and it failed.
FAILED: bindings/ocaml/llvm/llvm.cma bindings/ocaml/llvm/libllvm.a bindings/ocaml/llvm/llvm.cmxa bindings/ocaml/llvm/llvm.a bindings/ocaml/llvm/llvm.cmi bindings/ocaml/llvm/llvm.cmo bindings/ocaml/llvm/llvm.cmx bindings/ocaml/llvm/llvm.o
cd /home/wowbagger/swift-source/build/Ninja-RelWithDebInfoAssert/llvm-linux-x86_64/bindings/ocaml/llvm && /usr/bin/ocamlfind ocamlmklib -o llvm -lstdc++ -ldopt -L/home/wowbagger/swift-source/build/Ninja-RelWithDebInfoAssert/llvm-linux-x86_64/./lib -ccopt "-L\\\$CAMLORIGIN/../.." -ccopt "-Wl,-rpath,\\\$CAMLORIGIN/../.." -custom -lLLVMCore -lLLVMRemarks -lLLVMBitstreamReader -lLLVMBinaryFormat -lLLVMSupport -lLLVMDemangle -l/usr/lib/x86_64-linux-gnu/libz.so -lrt -ldl -ltinfo -lpthread -lm -ldopt "-Wl,-rpath,\\\$ORIGIN/../../../lib" llvm.mli llvm.ml llvm_ocaml.o
x86_64-linux-gnu-ar: invalid option -- '/'
Usage: x86_64-linux-gnu-ar [emulation options] [-]{dmpqrstx}[abcDfilMNoOPsSTuvV] [--plugin <name>] [member-name] [count] archive-file file...
x86_64-linux-gnu-ar -M [<mri-script]
commands:
d - delete file(s) from the archive
m[ab] - move file(s) in the archive
p - print file(s) found in the archive
q[f] - quick append file(s) to the archive
r[ab][f][u] - replace existing or insert new file(s) into the archive
s - act as ranlib
t[O][v] - display contents of the archive
x[o] - extract file(s) from the archive
command specific modifiers:
[a] - put file(s) after [member-name]
[b] - put file(s) before [member-name] (same as [i])
[D] - use zero for timestamps and uids/gids (default)
[U] - use actual timestamps and uids/gids
[N] - use instance [count] of name
[f] - truncate inserted file names
[P] - use full path names when matching
[o] - preserve original dates
[O] - display offsets of files in the archive
[u] - only replace files that are newer than current archive contents
generic modifiers:
[c] - do not warn if the library had to be created
[s] - create an archive index (cf. ranlib)
[S] - do not build a symbol table
[T] - make a thin archive
[v] - be verbose
[V] - display the version number
@<file> - read options from <file>
--target=BFDNAME - specify the target object format as BFDNAME
--output=DIRNAME - specify the output directory for extraction operations
optional:
--plugin <p> - load the specified plugin
emulation options:
No emulation specific options
x86_64-linux-gnu-ar: supported targets: elf64-x86-64 elf32-i386 elf32-iamcu elf32-x86-64 pei-i386 pei-x86-64 elf64-l1om elf64-k1om elf64-little elf64-big elf32-little elf32-big pe-x86-64 pe-bigobj-x86-64 pe-i386 srec symbolsrec verilog tekhex binary ihex plugin
[19/2079][ 0%][0.045s] Generating VCSRevision.h
-- Found Git: /usr/bin/git (found version "2.25.1")
[30/2071][ 1%][4.462s] Building CXX object utils/benchmark/src/CMakeFiles/benchmark.dir/benchmark_register.cc.o
ninja: build stopped: subcommand failed.
ERROR: command terminated with a non-zero exit status 1, aborting