treewide: change fetchCargoTarball default to opt-out

[bhipple]

Changes the default fetcher in the Rust Platform to be the newer
fetchCargoTarball, and changes every application using the current default to
instead opt out.

This commit does not change any hashes or cause any rebuilds. Once integrated,
we will start deleting the opt-outs and recomputing hashes.

See #79975 for details.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[bhipple]

There are no manual changes in this PR; the diff is generated with the following script, which you're welcome to review in addition to the actual diff:
https://github.com/bhipple/dotfiles/blob/master/bin/fix-rust-p2.sh

In order to check for diffs, this script can be run to build a number of packages on master and then again after running the above script:
https://github.com/bhipple/dotfiles/blob/master/bin/fix-rust-p2-check.sh

Current output looks like this:

$ fix-rust-p2-check.sh
+ cd /home/bhipple/src/nixpkgs
+ git checkout -f master
Switched to branch 'master'
Your branch is up to date with 'origin/master'.
+ git clean -ffdx
Removing new/
Removing old/
+ ATTRS=(broot fido2luks gitAndTools.git-workspace hexdino mdsh nix-du tre-command wagyu cargo exa nix-index ripgrep rustc rx termplay ja2-stracciatella parity tree-sitter)
+ mkdir -p old new
+ nix build -L -f . broot fido2luks gitAndTools.git-workspace hexdino mdsh nix-du tre-command wagyu cargo exa nix-index ripgrep rustc rx termplay ja2-stracciatella parity tree-sitter
+ mv result result-1 result-10 result-11 result-12 result-13 result-14 result-15 result-16 result-17 result-2 result-3 result-4 result-5 result-6 result-7 result-8 result-9 old/
+ fix-rust-p2.sh
Already on 'master'
Your branch is up to date with 'origin/master'.
+ nix build -L -f . broot fido2luks gitAndTools.git-workspace hexdino mdsh nix-du tre-command wagyu cargo exa nix-index ripgrep rustc rx termplay ja2-stracciatella parity tree-sitter
+ mv result result-1 result-10 result-11 result-12 result-13 result-14 result-15 result-16 result-17 result-2 result-3 result-4 result-5 result-6 result-7 result-8 result-9 new/
+ set +x
old
├── result -> /nix/store/isxbiasgzwalpjf4n4k92m2zc9lam67n-broot-0.13.1
├── result-1 -> /nix/store/jdyd1ira6sd4qrjqzgvngkz51zs5kfna-fido2luks-0.2.3
├── result-10 -> /nix/store/dan48igpc9zxplgc03057bdcjs5giby5-nix-index-0.1.2
├── result-11 -> /nix/store/5aj0ajqhwcfahgrz1nrflb39jr36gsj7-ripgrep-11.0.2
├── result-12 -> /nix/store/y41n9f36mhvsv6jr1fxfxgl781lhcz15-rustc-1.41.0
├── result-13 -> /nix/store/qs2gvhrhya62q9lcfsk2dgi8asc20s3j-rx-0.3.2
├── result-14 -> /nix/store/v8z8lb5f6mm6j2dksskncrdvrf3cdsi4-termplay-2.0.6
├── result-15 -> /nix/store/amjbisn3f0brb7g9gbks6zidq4f6irzl-ja2-stracciatella-0.16.1
├── result-16 -> /nix/store/7qn6ly7k9c0p269qckqzp6nf5767v0y0-parity-2.5.11
├── result-17 -> /nix/store/zdq97hi4fzcrqqfdcd1p93c12pjqkkfj-tree-sitter-0.15.7
├── result-2 -> /nix/store/d1apq07p5xc3qd3j7c1hx5vy6pqg9a5i-git-workspace-0.5.0
├── result-3 -> /nix/store/2zpwpqj60wjzlj1vggihp9snqzjy6jxv-hexdino-0.1.0
├── result-4 -> /nix/store/0j3igiwm5hd9yn2hmrzb7ck6s73vvx65-mdsh-0.3.0
├── result-5 -> /nix/store/51jfdd5rcy0qryxfhr5vavbfgvi6w50c-nix-du-0.3.1
├── result-6 -> /nix/store/4xrlbs7fpakm2yja3fg3wv1c3w9xqnaf-tre-0.2.2
├── result-7 -> /nix/store/lvcd0pkxnc274gqwaxn2z37hx8xfxg99-wagyu-0.6.1
├── result-8 -> /nix/store/7v2q1yrixn7qb7gbscxcqn2xw36mlaxy-cargo-1.41.0
└── result-9 -> /nix/store/icly3vax74dq60dmyn5879wpvqx5dd3l-exa-0.9.0
new
├── result -> /nix/store/isxbiasgzwalpjf4n4k92m2zc9lam67n-broot-0.13.1
├── result-1 -> /nix/store/jdyd1ira6sd4qrjqzgvngkz51zs5kfna-fido2luks-0.2.3
├── result-10 -> /nix/store/dan48igpc9zxplgc03057bdcjs5giby5-nix-index-0.1.2
├── result-11 -> /nix/store/5aj0ajqhwcfahgrz1nrflb39jr36gsj7-ripgrep-11.0.2
├── result-12 -> /nix/store/y41n9f36mhvsv6jr1fxfxgl781lhcz15-rustc-1.41.0
├── result-13 -> /nix/store/qs2gvhrhya62q9lcfsk2dgi8asc20s3j-rx-0.3.2
├── result-14 -> /nix/store/v8z8lb5f6mm6j2dksskncrdvrf3cdsi4-termplay-2.0.6
├── result-15 -> /nix/store/amjbisn3f0brb7g9gbks6zidq4f6irzl-ja2-stracciatella-0.16.1
├── result-16 -> /nix/store/7qn6ly7k9c0p269qckqzp6nf5767v0y0-parity-2.5.11
├── result-17 -> /nix/store/zdq97hi4fzcrqqfdcd1p93c12pjqkkfj-tree-sitter-0.15.7
├── result-2 -> /nix/store/d1apq07p5xc3qd3j7c1hx5vy6pqg9a5i-git-workspace-0.5.0
├── result-3 -> /nix/store/2zpwpqj60wjzlj1vggihp9snqzjy6jxv-hexdino-0.1.0
├── result-4 -> /nix/store/0j3igiwm5hd9yn2hmrzb7ck6s73vvx65-mdsh-0.3.0
├── result-5 -> /nix/store/51jfdd5rcy0qryxfhr5vavbfgvi6w50c-nix-du-0.3.1
├── result-6 -> /nix/store/4xrlbs7fpakm2yja3fg3wv1c3w9xqnaf-tre-0.2.2
├── result-7 -> /nix/store/lvcd0pkxnc274gqwaxn2z37hx8xfxg99-wagyu-0.6.1
├── result-8 -> /nix/store/7v2q1yrixn7qb7gbscxcqn2xw36mlaxy-cargo-1.41.0
└── result-9 -> /nix/store/icly3vax74dq60dmyn5879wpvqx5dd3l-exa-0.9.0

36 directories, 0 files
********************************************************************************
Diff
No hash diff generated. Success!

I've reviewed the diff as well and the rest of them look cookie-cutter, but if there's any one you're suspicious of let me know and I will verify that this PR does not change its hash or cause any rebuilds.

[bhipple]

@GrahamcOfBorg build ripgrep nix-du

@GrahamcOfBorg eval

[bhipple]

This is the actual change on the PR. Once merged I'll send another one updating the manual and deleting this doc comment.

Since the PR is so big and likely to generate merge conflicts as others submit PRs bumping Rust applications, for now I've just stuck to a diff that can be programmatically regenerated after a hard reset to origin/master, though I could make the sed smarter.

[bhipple]

Nice to see ofborg agrees this causes 0 rebuilds :)

CC @worldofpeace @disassembler once merged I'll backport this to 20.03, but doing so requires #79981 first (which has the implementation, defaulted to false, and the removeAttrs fixes to allow this PR to be a clean no-rebuild change).

[worldofpeace]

Nice to see ofborg agrees this causes 0 rebuilds :)

CC @worldofpeace @disassembler once merged I'll backport this to 20.03, but doing so requires #79981 first (which has the implementation, defaulted to false, and the removeAttrs fixes to allow this PR to be a clean no-rebuild change).

I approved it, but I will defer integration to those who are informed.

[zimbatm]

nice!

[jonringer]

there are several merge conflicts, it would probably be prudent to get this in ASAP

[worldofpeace]

there are several merge conflicts, it would probably be prudent to get this in ASAP

I believe it was mentioned the diff can be programmatically regenerated #79978 (comment)

[bhipple]

Did a git fetch; git reset --hard origin/master, re-applied the diff generator, and pushed to PR. As before, no manual changes and no expected hash changes/rebuilds.

I also re-ran the fix-rust-p2-check.sh script posted above and verified there are still no rebuilds on the ~20 Rust packages I'm spot-checking.

[bhipple]

Went into conflict again; rebase and re-regenerated the diff again :)

[jonringer]

changes seems to be in anticipation to changes in the rust ecosystem.

LGTM