R trace does not work correctly inside functions?

Question

tracedoesn't seem to work correctly inside precompiled functions

For example, in this fragment

xx <- 2:7
nu <- seq(-10, 9, length.out = 2001)
op <- par(lab = c(16, 5, 7))
matplot(nu, t(outer(xx, nu, besselI)), type = "l", ylim = c(-50, 200),
        main = expression(paste("Bessel ", I[nu](x), " for fixed ", x,
                                ",  as ", f(nu))),
        xlab = expression(nu))

Simple traceto xy.coordswork fine

trace(xy.coords)
matplot(nu, t(outer(xx, nu, besselI)), type = "l", ylim = c(-50, 200),
        main = expression(paste("Bessel ", I[nu](x), " for fixed ", x,
                                ",  as ", f(nu))),
        xlab = expression(nu))
# trace: xy.coords
# trace: xy.coords
# trace: xy.coords
# trace: xy.coords
# trace: xy.coords
# trace: xy.coords
# trace: xy.coords

But tracing with the function does not work

trace(xy.coords, tracer = quote(cat("test\n")))
# Tracing function "xy.coords" in package "grDevices"
# [1] "xy.coords"
matplot(nu, t(outer(xx, nu, besselI)), type = "l", ylim = c(-50, 200),
        main = expression(paste("Bessel ", I[nu](x), " for fixed ", x,
                                ",  as ", f(nu))),
        xlab = expression(nu))

While direct calling works fine

xy.coords(1:3, 1:2, recycle = TRUE)
# Tracing xy.coords(1:3, 1:2, recycle = TRUE) on entry 
# test
# $x
# [1] 1 2 3
# 
# $y
# [1] 1 2 1
# 
# $xlab
# NULL
# 
# $ylab
# NULL

What is happening and what do I need to change?

Refresh . I will disable compilation of packages grDevicesand others base, but tracestill not working correctly. When debugging matplot, xy.coordsit turns out to be without tracing.

Update 2 . This is similar to Overriding a function imported in a namespace , but after you have tried everything with a traced object proposed in the namespace, the old one is still called.

Answer 1

( matplot), , :

xx <- 2:7
nu <- seq(-10, 9, length.out = 2001)
op <- par(lab = c(16, 5, 7))

trace(xy.coords, tracer = quote(cat("test\n")))

# get the imports env of graphics
nsi <- parent.env(getNamespace('graphics'))

unlockBinding("xy.coords", nsi)
assign('xy.coords', xy.coords, nsi)

matplot(nu, t(outer(xx, nu, besselI)), type = "l", ylim = c(-50, 200),
        main = expression(paste("Bessel ", I[nu](x), " for fixed ", x,
                                ",  as ", f(nu))),
        xlab = expression(nu))


Tracing xy.coords(x, y, xlabel, ylabel, log = log) on entry 
test
Tracing xy.coords(x, y, xlabel, ylabel, log) on entry 
test
Tracing xy.coords(x, y) on entry 
test
Tracing xy.coords(x, y) on entry 
test
Tracing xy.coords(x, y) on entry 
test
Tracing xy.coords(x, y) on entry 
test
Tracing xy.coords(x, y) on entry 
test