Why isn't broom::glance working with the gam package? - r

Question

If I try to run an example from the broom package PDF, I'm getting an error. This is because mgcv is being loaded by the car package. However, even when I after I unload car and mgcv, broom::glance still fails.
How can I get the broom package work with gam::gam and have other packages loaded?
library(reshape2); library(plyr); library(stringr); library(lubridate);
library(knitr); library(sp); library(rgeos); library(lme4); library(formatR);
library(rgdal); library(ggmap); library(maptools); library(Hmisc); library(raster);
library(car); library(extrafont); library(openNLP); library(effects); library(psych);
library(MuMIn); library(GPArotation); library(tuneR); library(gdata); library(xlsx);
library(combinat); library(stargazer); library(grid); library(scales); library(dplyr);
library(english); library(repmis); library(pscl); library(testthat); library(broom);
library(ggplot2); library(geosphere); library(moult); library(GGally); library(pavo);
library(stringi); library(mgcv); library(gam)
detach(package:car, unload = TRUE)
detach(package:mgcv, unload = TRUE)
if (require("gam", quietly = TRUE)) {
data(kyphosis)
g <- gam::gam(Kyphosis ~ s(Age,4) + Number, family = binomial, data = kyphosis)
tidy(g)
augment(g)
glance(g)
}
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Warning: namespace ‘mgcv’ is not available and has been replaced
by .GlobalEnv when processing object ‘kyphosis’
Error in `$<-.data.frame`(`*tmp*`, "logLik", value = numeric(0)) :
replacement has 0 rows, data has 1