Booker claim by challenging the Guidelines’ constitutionality in the district court. We review alleged violations of the Sixth Amendment’s Confrontation Clause de novo. United States v. Rondeau, 430 F.3d 44, 47 (1st Cir.2005). Boulais’ arguments for a remand for resentencing come down to three propositions. We find none to be meritorious. First, Boulais claims Booker error because the district court conducted a Guidelines analysis of his potential sentence. Such an error exists when a “defendant’s Guidelines sentence was imposed under a mandatory system.” United States v. Antonakopoulos, 399 F.3d 68, 75 (1st Cir. 2005). However, Boulais’ sentence was imposed under the ACCA, not the Guidelines, and hence Booker does not apply. See United States v. Ivery, 427 F.3d 69, 71 (1st Cir.2005) (<HOLDING>); United States v. Sanchez-Berrios, 424 F.3d
holding that because the portions of the guidelines dealing with revocation of supervised release were deemed advisory even before booker and remain so resort to them cannot constitute booker error recognizing that under booker judges should continue to take account of the guidelines together with other sentencing goals  and a sentencing court must at least consider the guidelines in fashioning a sentence quoting booker 125 sct at 764 holding that there is no nonconstitutional error under booker where the district court sentencing in the alternative sufficiently considered the guidelines as well as the other factors listed in  3553a holding petitions under 28 usc  2255 unavailable to advance booker claims in the absence of a supreme court decision rendering booker retroactive holding sentencing under the acca not to be a booker error