'guix package' processes command-line %actions in reverse

Hi,

Let consider:

$ guix package -S 17 -d 18

but

$ guix package -d 18 -S 17

does not the same thing. The '%actions' (roll-back, delete-generation,

switch-generation) are processed in reversed order as they appear on the

command-line -- because 'for-each' and 'assoc-ref'.

However, the transaction plan is always the same:

step0 process %actions

step1 remove

step2 install

step3 manifest

Therefore, I propose to split the 'for-each' on '%actions' (step0) into

fixed steps, such as the transaction always happens using this plan:

1. roll-back

2. switch-generation

3. delete-generation

4. remove

5. install

6. manifest

whatever the order in the command line.

On one hand, it reduces the "power" of combining '-S', '-d' and

'--roll-back'. On the other hand, it enforces commutativity which is

somehow what we want a transaction to be.

WDYT? I can come up with a patch. This initial issue had been reported

by bug#40549 [1].

(Note that an issue about short-name with optional argument can also

happen and tracked by bug#50472 [2].)

All the best,

simon

1: http://issues.guix.gnu.org/40549

2: http://issues.guix.gnu.org/50472

retitle 50473 'guix package' processes command-line %actions in reverse

thanks

('Failed to set the title of 50473: Non-printable characters are not

allowed in bug titles.' -- FFS...)