solana-sysvar is used at run time in 112 crates (of which 7 optionally). It is a direct run-time dependency in 18 crates. It's used only as a dev dependency in 15 crates (of which 4 directly).

Depender (with downloads and own rev deps) solana-sysvar version
519K 80 spl-token-2022 ^2.2.1
453K 375 spl-token ^2.2.0
360K 619 solana-program ^2.2.1
180K 2 spl-elgamal-registry ^2.2.1
169K 37 solana-program-runtime ^2.2.1
159K 120 solana-account-decoder =2.2.1
224K 89 solana-account optional ^2.2.1
42K 28 solana-stake-program =2.2.1
39K 22 solana-bpf-loader-program =2.2.1
38K 10 solana-system-program =2.2.1
15K 27 solana-cli-output =2.2.1
2.7K 4 litesvm ^2.2
1.8K 3 solana-cli =2.2.1
1.7K 6 mollusk-svm ^2.2
150 solana-hbase-writer =2.2.1
120 spherenet-program ^2.2.1
374K 5 spl-program-error dev ^2.2.1
133K 45 solana-message dev ^2.2.1
91K 3 solana-reserved-account-keys dev ^2.2.1
37K 5 solana-loader-v4-program dev =2.2.1
22K 10 solana-svm dev =2.2.1
8.0K 12 agave-reserved-account-keys dev ^2.2.1