[~/myprogs/test 1]$ ls
main.go
[~/myprogs/test 1]$ cat main.go
package main

import "fmt"

func main() {
	fmt.Println("hello!")
}

[~/myprogs/test 1]$ go build -asmflags="all=-trimpath=`pwd`"

[~/myprogs/test 1]$ go build -asmflags="all=-trimpath=`pwd`"
# runtime/internal/atomic
usage: asm [options] file.s ...
Flags:
  -D value
    	predefined symbol with optional simple value -D=identifier=value; can be set multiple times
  -I value
    	include directory; can be set multiple times
  -S	print assembly and machine code
  -V	print version and exit
  -debug
    	dump instructions as they are parsed
  -dynlink
    	support references to Go symbols defined in other shared libraries
  -e	no limit on number of errors reported
  -gensymabis
    	write symbol ABI information to output file, don't assemble
  -newobj
    	use new object file format
  -o string
    	output file; default foo.o for /a/b/c/foo.s as first argument
  -shared
    	generate code that can be linked into a shared library
  -trimpath string
    	remove prefix from recorded source file paths
# internal/cpu
usage: asm [options] file.s ...
Flags:
  -D value
    	predefined symbol with optional simple value -D=identifier=value; can be set multiple times
  -I value
    	include directory; can be set multiple times
  -S	print assembly and machine code
  -V	print version and exit
  -debug
    	dump instructions as they are parsed
  -dynlink
    	support references to Go symbols defined in other shared libraries
  -e	no limit on number of errors reported
  -gensymabis
    	write symbol ABI information to output file, don't assemble
  -newobj
    	use new object file format
  -o string
    	output file; default foo.o for /a/b/c/foo.s as first argument
  -shared
    	generate code that can be linked into a shared library
  -trimpath string
    	remove prefix from recorded source file paths
# sync/atomic
usage: asm [options] file.s ...
Flags:
  -D value
    	predefined symbol with optional simple value -D=identifier=value; can be set multiple times
  -I value
    	include directory; can be set multiple times
  -S	print assembly and machine code
  -V	print version and exit
  -debug
    	dump instructions as they are parsed
  -dynlink
    	support references to Go symbols defined in other shared libraries
  -e	no limit on number of errors reported
  -gensymabis
    	write symbol ABI information to output file, don't assemble
  -newobj
    	use new object file format
  -o string
    	output file; default foo.o for /a/b/c/foo.s as first argument
  -shared
    	generate code that can be linked into a shared library
  -trimpath string
    	remove prefix from recorded source file paths