I do not maintain bash, so I can't say why putting in the semicolon works when a <newline> without the semicolon doesn't work.

If you compare the ksh -xv script trace output to the bash -xv script trace output when running your script, the difference in what the trace of the eval showed made me wonder if a semicolon would make a difference. So I tried it, and it worked. The bash trace output looked like it was executing the command:

Code:

eval export BASEPATH=/masterdir export TESTPATH=${BASEPATH}/subdir

after the command substitution, but it didn't export a variable named "export" either.

Even if bash is executing your script (without the double quotes) as:

Code:

eval export BASEPATH=/masterdir
export TESTPATH=${BASEPATH}/subdir

both export commands clearly have to be evaluated by the the shell in order. And with those two export statements, the result should be the same whether or not the 2nd export is evaluated by the eval or processed as a stand-alone command. Furthermore, if you look at $BASEPATH after the eval completes (with or without the double quotes), you'll see that BASEPATH is set correctly. It just looks like bash executes the 2nd export command before it executes the 1st export command. And, that appears to me to be a bug.