[BUG] /usr/bin/echo eats "-E", but amber does not handle the case

[lens0021]

Describe the bug

/usr/bin/echo eats the token "-E" because it seems to be [SHORT-OPTION] of echo. So the next things happen:

1. echo "-E" prints nothing.
2. let flag = "-E" sets flag as ""

To Reproduce

amber eval -- 'echo "-E"'
amber eval -- 'const flag = "-E"; echo flag'

The both commands print nothing.

Expected behavior
-E should be printed.

Additional context
Because of this, the next flag is set as "-r" or "", so that the replace_regex does not work as expected.

amber/src/std/text.ab

Line 23 in cba1671

let flag = status == 0 then "-r" else "-E"

[Mte90]

What is the bash generated?

[lens0021]

amber echo "-e" is compiled to bash echo "-e" currently. But it should be echo -- "-e".

From man echo: > -e Enable interpretation of backslash escapes. > > Unlike other shells, this echo accepts -- to signal the end of the options.

(Edited: -- is from the fish shell built in echo)

[lens0021]

amber let flag = "-E"; echo flag → bash __0_flag="-E"; echo "${__0_flag}" and the output is also empty.

One solution I can think is replacing echo {} with printf "%s\n" {}, but I cannot tell it has no side effects.

[Mte90]

@hdwalters what do you think?