Running examples in ‘rvest-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: html_table
> ### Title: Parse an html table into a data frame.
> ### Aliases: html_table
> 
> ### ** Examples
> 
> tdist <- read_html("http://en.wikipedia.org/wiki/Student%27s_t-distribution")
> tdist %>%
+   html_node("table.infobox") %>%
+   html_table(header = FALSE)
                                 X1
1      Probability density function
2  Cumulative distribution function
3                        Parameters
4                           Support
5                               PDF
6                               CDF
7                              Mean
8                            Median
9                              Mode
10                         Variance
11                         Skewness
12                     Ex. kurtosis
13                          Entropy
14                              MGF
15                               CF
                                                                                                                                                                                                                                                                                                                                                                                                         X2
1                                                                                                                                                                                                                                                                                                                                                                              Probability density function
2                                                                                                                                                                                                                                                                                                                                                                          Cumulative distribution function
3                                                                                                                                                                                                                                                                                                                                                     ν>0{\\displaystyle \\nu >0} degrees of freedom (real)
4                                                                                                                                                                                                                                                                                                                                                                                              x ∈ (−∞; +∞)
5                                                                                                                                                    Γ(ν+12)νπΓ(ν2)(1+x2ν)−ν+12{\\displaystyle \\textstyle {\\frac {\\Gamma \\left({\\frac {\\nu +1}{2}}\\right)}{{\\sqrt {\\nu \\pi }}\\,\\Gamma \\left({\\frac {\\nu }{2}}\\right)}}\\left(1+{\\frac {x^{2}}{\\nu }}\\right)^{-{\\frac {\\nu +1}{2}}}\\!}
6  12+xΓ(ν+12)×2F1(12,ν+12;32;−x2ν)πνΓ(ν2){\\displaystyle {\\begin{matrix}{\\frac {1}{2}}+x\\Gamma \\left({\\frac {\\nu +1}{2}}\\right)\\times \\\\[0.5em]{\\frac {\\,_{2}F_{1}\\left({\\frac {1}{2}},{\\frac {\\nu +1}{2}};{\\frac {3}{2}};-{\\frac {x^{2}}{\\nu }}\\right)}{{\\sqrt {\\pi \\nu }}\\,\\Gamma \\left({\\frac {\\nu }{2}}\\right)}}\\end{matrix}}}\nwhere 2F1 is the hypergeometric function
7                                                                                                                                                                                                                                                                                                                                                    0 for ν>1{\\displaystyle \\nu >1}, otherwise undefined
8                                                                                                                                                                                                                                                                                                                                                                                                         0
9                                                                                                                                                                                                                                                                                                                                                                                                         0
10                                                                                                                                                                                                                                              νν−2{\\displaystyle \\textstyle {\\frac {\\nu }{\\nu -2}}} for ν>2{\\displaystyle \\nu >2}, ∞ for 1<ν≤2{\\displaystyle 1<\\nu \\leq 2}, otherwise undefined
11                                                                                                                                                                                                                                                                                                                                                   0 for ν>3{\\displaystyle \\nu >3}, otherwise undefined
12                                                                                                                                                                                                                                                  6ν−4{\\displaystyle \\textstyle {\\frac {6}{\\nu -4}}} for ν>4{\\displaystyle \\nu >4}, ∞ for 2<ν≤4{\\displaystyle 2<\\nu \\leq 4}, otherwise undefined
13            ν+12[ψ(1+ν2)−ψ(ν2)]+ln⁡[νB(ν2,12)](nats){\\displaystyle {\\begin{matrix}{\\frac {\\nu +1}{2}}\\left[\\psi \\left({\\frac {1+\\nu }{2}}\\right)-\\psi \\left({\\frac {\\nu }{2}}\\right)\\right]\\\\[0.5em]+\\ln {\\left[{\\sqrt {\\nu }}B\\left({\\frac {\\nu }{2}},{\\frac {1}{2}}\\right)\\right]}\\,{\\scriptstyle {\\text{(nats)}}}\\end{matrix}}}\nψ: digamma function,\nB: beta function
14                                                                                                                                                                                                                                                                                                                                                                                                undefined
15                                                                             Kν/2(ν|t|)⋅(ν|t|)ν/2Γ(ν/2)2ν/2−1{\\displaystyle \\textstyle {\\frac {K_{\\nu /2}\\left({\\sqrt {\\nu }}|t|\\right)\\cdot \\left({\\sqrt {\\nu }}|t|\\right)^{\\nu /2}}{\\Gamma (\\nu /2)2^{\\nu /2-1}}}} for ν>0{\\displaystyle \\nu >0}\nKν(x){\\displaystyle K_{\\nu }(x)}: Modified Bessel function of the second kind[1]
> 
> births <- read_html("https://www.ssa.gov/oact/babynames/numberUSbirths.html")
Error in open.connection(x, "rb") : 
  gnutls_handshake() failed: Error in the push function.
Calls: read_html -> read_html.default
Execution halted