solana-sysvar is used at run time in 112 crates (of which 6 optionally). It is a direct run-time dependency in 18 crates. It's used only as a dev dependency in 16 crates (of which 4 directly).

Depender (with downloads and own rev deps) solana-sysvar version
532K 80 spl-token-2022 ^2.2.1
455K 374 spl-token ^2.2.0
362K 611 solana-program ^2.2.1
180K 2 spl-elgamal-registry ^2.2.1
169K 37 solana-program-runtime ^2.2.1
159K 119 solana-account-decoder =2.2.1
230K 44 solana-account optional ^2.2.1
43K 28 solana-stake-program =2.2.1
41K 22 solana-bpf-loader-program =2.2.1
40K 10 solana-system-program =2.2.1
16K 27 solana-cli-output =2.2.1
2.7K 4 litesvm ^2.2
1.7K 6 mollusk-svm ^2.2
1.4K 3 solana-cli =2.2.1
120 spherenet-program ^2.2.1
solana-hbase-writer =2.2.1
375K 5 spl-program-error dev ^2.2.1
138K 45 solana-message dev ^2.2.1
99K 3 solana-reserved-account-keys dev ^2.2.1
39K 5 solana-loader-v4-program dev =2.2.1
23K 10 solana-svm dev =2.2.1
5.9K 12 agave-reserved-account-keys dev ^2.2.1