我已经使用httr将数据从REDCap数据库导出到R中几个月了。我们最近将R Studio服务器升级到最新版本（v0.98.1049）并同时升级到R 3.1.1。升级后，我的httr::POST调用有时会停止工作。我一直得到的错误是
Error in function (type, msg, asError = TRUE) :
GnuTLS recv error (-9): A TLS packet with unexpected length was received.
起初我认为这可能是一个SSL问题，但错误只发生在某些数据库中，在这些数据库中，我仍然可以使用RCurl下载数据。也就是说，此代码将起作用
RCurl::postForm(uri=[URL],
.params=list(token=[TOKEN],
content='record',
format='csv'))
但是这段代码不会
httr::POST(url=[URL],
body=list(token=[TOKEN],
content='record',
format='csv'))
进一步引起我的困惑，即使我无法在发生此错误的项目中导出数据，我也可以导入数据。
我没有关于从哪里开始的想法。我很欣赏这里可能出现问题的任何想法。
（我想提供一个可重现的例子，但我担心我会使用医疗保健数据。抱歉）
根据要求，这里是verbose（）输出。这是一个稍微不同的调用，但会产生相同的错误。 （我使用的呼叫不会暴露机密信息）
> httr::POST(url=whi$url,
+ body=list(token=whi$token,
+ content='metadata',
+ format='csv'),
+ httr::verbose(data_in=TRUE, info=TRUE))
* Hostname was found in DNS cache
* Hostname in DNS cache was stale, zapped
* Trying 172.26.30.4...
* Connected to [URL] (172.26.30.4) port 443 (#7)
* found 153 certificates in /home/nutterb/R/x86_64-unknown-linux-gnu-library/3.1/httr/cacert.pem
* SSL re-using session ID
* server certificate verification OK
* common name: [URL] (matched)
* server certificate expiration date OK
* server certificate activation date OK
* certificate public key: RSA
* certificate version: #3
* subject: OU=Domain Control Validated,CN=[URL]
* start date: Thu, 10 Apr 2014 17:06:17 GMT
*
* expire date: Sat, 21 Mar 2015 16:35:07 GMT
*
* issuer: C=US,ST=Arizona,L=Scottsdale,O=Starfield Technologies\, Inc.,OU=http://certs.starfieldtech.com/repository/,CN=Starfield Secure Certificate Authority - G2
* compression: NULL
* cipher: AES-128-CBC
* MAC: SHA1
-> POST /redcap/api/ HTTP/1.1
-> User-Agent: curl/7.35.0 Rcurl/1.95.4.1 httr/0.5.0.9000
-> Host: [URL]
-> Accept-Encoding: gzip
-> accept: application/json, text/xml, */*
-> Content-Length: 374
-> Expect: 100-continue
-> Content-Type: multipart/form-data; boundary=------------------------05c968969cc362a9
->
<- HTTP/1.1 100 Continue
>> --------------------------05c968969cc362a9
>> Content-Disposition: form-data; name="token"
>>
>> [TOKEN]
>> --------------------------05c968969cc362a9
>> Content-Disposition: form-data; name="content"
>>
>> metadata
>> --------------------------05c968969cc362a9
>> Content-Disposition: form-data; name="format"
>>
>> csv
>> --------------------------05c968969cc362a9--
<- HTTP/1.1 200 OK
<- Date: Sat, 06 Sep 2014 09:55:43 GMT
<- Expires: 0
<- cache-control: no-store, no-cache, must-revalidate
<- Pragma: no-cache
<- Access-Control-Allow-Origin: *
<- Vary: Accept-Encoding
<- Content-Type: text/html; charset=utf-8
<- Connection: close
<- Content-Encoding: gzip
<-
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
<< NA
* GnuTLS recv error (-9): A TLS packet with unexpected length was received.
* Closing connection 7
Error in function (type, msg, asError = TRUE) :
GnuTLS recv error (-9): A TLS packet with unexpected length was received.
In addition: There were 11 warnings (use warnings() to see them)
> warnings()
Warning messages:
1: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
2: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
3: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
4: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
5: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
6: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
7: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
8: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
9: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
10: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
11: In strsplit(x, "\n", fixed = TRUE) : input string 1 is invalid in this locale
>