pkg/59842: cwrappers doesn't transform if "cc @command-line-aguments" syntax is used

>Number:         59842
>Category:       pkg
>Synopsis:       cwrappers doesn't transform if "cc @command-line-aguments" syntax is used
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 16 04:05:00 +0000 2025
>Originator:     coypu
>Release:        pkgsrc-current as of 2025-12-15, cwrappers-20220403
>Organization:
>Environment:
NetBSD  10.1 NetBSD 10.1 (GENERIC) #0: Mon Dec 16 13:08:11 UTC 2024  [email protected]:/usr/src/sys/arch/amd64/compile/GENERIC amd64

>Description:
Here is a reproducer trying to build things "normally" and then with @command-line-arguments. Both are using -lnonexistent, which should be removed by cwrappers config, but isn't in the second case.

A package (mongodb) was using this syntax to avoid exceeding max command line length.

#!/bin/sh

set -ex

cat << EOF > main.c
int main() { return 0; }
EOF

cat << EOF > cc
worklog=.work.log
exec=/usr/bin/cc
exec_path=/usr/pkg/libexec/cwrappers/cc-wrapper
transform=rm:-lnonexistent
EOF

cat << EOF > mainlink
main.c -lnonexistent
EOF

# Normal command, works fine
env CWRAPPERS_CONFIG_DIR=. /usr/pkg/libexec/cwrappers/cc-wrapper main.c -lnonexistent

# Same command passed with '@mainlink', transform doesn't work
env CWRAPPERS_CONFIG_DIR=. /usr/pkg/libexec/cwrappers/cc-wrapper '@mainlink'
>How-To-Repeat:

>Fix: