If you change builder.copyFile to do

    _, err = io.Copy(df, sf)
    if strings.Contains(df.Name(), "unicode.a") {
        err = io.ErrShortWrite
    }

and then run all.bash, the error appears mixed with the
other output and is barely noticeable.  And then make.bash
just stops for no apparent reason.



# Building packages and commands for linux/amd64.
runtime
errors
sync/atomic
unicode
unicode/utf8
math
unicode/utf16
sync
crypto/subtle
container/list
io
syscall
hash
crypto
crypto/md5
hash/crc32
crypto/cipher
short write     <<<<<<< BET YOU DIDN'T NOTICE THAT!
crypto/hmac
crypto/sha1
hash/adler32
container/ring
crypto/sha256
crypto/sha512
exp/norm
time
exp/terminal
exp/utf8string
hash/crc64
hash/fnv
image/color
os
sort
math/rand
strconv
math/cmplx
container/heap
os/signal
reflect
encoding/base64
crypto/aes
crypto/rc4
encoding/ascii85
encoding/base32
fmt
encoding/binary
debug/dwarf
crypto/des
flag
go/token
log
debug/pe
database/sql/driver
testing/iotest
database/sql