portage-ng --fetchonly
>>> Emerging : portage://dev-lang/spidermonkey-140.16.0:run?{[]}
These are the packages that would be merged, in order:
Calculating dependencies... done!
└─step 1─┤ useflag portage://dev-lang/rust-bin-1.94.1 (llvm_slot_21)
└─step 2─┤ download portage://dev-lang/rust-bin-1.94.1
│ └─ file ─┤ 183.38 Mb rust-1.94.1-x86_64-unknown-linux-gnu.tar.xz
│ download portage://dev-lang/spidermonkey-140.16.0
│ └─ file ─┤ 603.28 Mb firefox-140.16.0esr.source.tar.xz
│ │ 15.26 Kb firefox-140esr-patches-13.tar.xz
│ │ 3.58 Kb spidermonkey-140-patches-02.tar.xz
│ download portage://dev-libs/nspr-4.40
│ └─ file ─┤ 985.34 Kb nspr-4.40.tar.gz
│ download portage://dev-util/cbindgen-0.29.4
│ └─ file ─┤ 6.06 Mb cbindgen-0.29.4-crates.tar.xz
│ │ 246.72 Kb cbindgen-0.29.4.tar.gz
Total: 5 actions (1 useflag, 4 downloads), grouped into 2 steps.
793.94 Mb to be downloaded.
>>> Assumptions taken during proving & planning:
USE flag change (1 package):
Add to /etc/portage/package.use:
dev-lang/rust-bin llvm_slot_21