fix build failure caused by imprecise libc version specification
more precisely describe permissable libc versions
.# [why]
libc >= v0.2.15 is needed for utmp support.
libc <= v0.2.66 is required to avoid build errors for MinSRV == 1.31.0.
Intermittant build failures were being caused by `cargo` using early libc versions.
@@ -21,7 +21,6 @@ getopts = "<= 0.2.21"
failure = { version = "<= 0.1.1", optional = true }
failure_derive = { version = "<= 0.1.1", optional = true }
time = { version = "<= 0.1.42", optional = true }
-libc = { version = "<= 0.2.66", optional = true }
wild = "2.0.1"
nix = { version = "<= 0.13", optional = true }
lazy_static = { version = "1.3", optional = true }
@@ -31,6 +30,9 @@ platform-info = { version = "<= 0.0.1", optional = true }
backtrace = ">= 0.3.3, <= 0.3.30"
# * data-encoding: require 2.1, but 2.2.0 breaks the build for MinSRV 1.31.0
data-encoding = { version = "~2.1", optional = true }
+# * libc: initial utmp support added in 0.2.15, but 0.2.68 break the build for MinSRV 1.31.0
+libc = { version = "0.2.15, <= 0.2.66", optional = true }
+
[target.'cfg(target_os = "redox")'.dependencies]
termion = "1.5"
